xref: /freebsd/contrib/tzdata/NEWS (revision 7ec2f6bce5d28e6662c29e63f6ab6b7ef57d98b2)
1News for the tz database
2
3Release 2020c - 2020-10-16 11:15:53 -0700
4
5  Briefly:
6    Fiji starts DST later than usual, on 2020-12-20.
7
8  Changes to future timestamps
9
10    Fiji will start DST on 2020-12-20, instead of 2020-11-08 as
11    previously predicted.  DST will still end on 2021-01-17.
12    (Thanks to Raymond Kumar and Alan Mintz.)  Assume for now that
13    the later-than-usual start date is a one-time departure from the
14    recent pattern.
15
16  Changes to build procedure
17
18    Rearguard tarballs now contain an empty file pacificnew.
19    Some older downstream software expects this file to exist.
20    (Problem reported by Mike Cullinan.)
21
22
23Release 2020b - 2020-10-06 18:35:04 -0700
24
25  Briefly:
26    Revised predictions for Morocco's changes starting in 2023.
27    Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08.
28    Macquarie Island has stayed in sync with Tasmania since 2011.
29    Casey, Antarctica is at +08 in winter and +11 in summer.
30    zic no longer supports -y, nor the TYPE field of Rules.
31
32  Changes to future timestamps
33
34    Morocco's spring-forward after Ramadan is now predicted to occur
35    no sooner than two days after Ramadan, instead of one day.
36    (Thanks to Milamber.)  The first altered prediction is for 2023,
37    now predicted to spring-forward on April 30 instead of April 23.
38
39  Changes to past and future timestamps
40
41   Casey Station, Antarctica has been using +08 in winter and +11 in
42   summer since 2018.  The most recent transition from +08 to +11 was
43   2020-10-04 00:01.  Also, Macquarie Island has been staying in
44   sync with Tasmania since 2011.  (Thanks to Steffen Thorsen.)
45
46  Changes to past and future time zone abbreviations and DST flags
47
48    Canada's Yukon, represented by America/Whitehorse and
49    America/Dawson, changes its time zone rules from -08/-07 to
50    permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it.
51    This change affects only the time zone abbreviation (MST vs PDT)
52    and daylight saving flag for the period between the two dates.
53    (Thanks to Andrew G. Smith.)
54
55  Changes to past timestamps
56
57    Correct several transitions for Hungary for 1918/1983.
58    For example, the 1983-09-25 fall-back was at 01:00, not 03:00.
59    (Thanks to Géza Nyáry.)  Also, the 1890 transition to standard
60    time was on 11-01, not 10-01 (thanks to Michael Deckers).
61
62    The 1891 French transition was on March 16, not March 15.  The
63    1911-03-11 French transition was at midnight, not a minute later.
64    Monaco's transitions were on 1892-06-01 and 1911-03-29, not
65    1891-03-15 and 1911-03-11.  (Thanks to Michael Deckers.)
66
67  Changes to code
68
69    Support for zic's long-obsolete '-y YEARISTYPE' option has been
70    removed and, with it, so has support for the TYPE field in Rule
71    lines, which is now reserved for compatibility with earlier zic.
72    These features were previously deprecated in release 2015f.
73    (Thanks to Tim Parenti.)
74
75    zic now defaults to '-b slim' instead of to '-b fat'.
76
77    zic's new '-l -' and '-p -' options uninstall any existing
78    localtime and posixrules files, respectively.
79
80    The undocumented and ineffective tzsetwall function has been
81    removed.
82
83  Changes to build procedure
84
85    The Makefile now defaults POSIXRULES to '-', so the posixrules
86    feature (obsolete as of 2019b) is no longer installed by default.
87
88  Changes to documentation and commentary
89
90    The long-obsolete files pacificnew, systemv, and yearistype.sh have
91    been removed from the distribution.  (Thanks to Tim Parenti.)
92
93
94Release 2020a - 2020-04-23 16:03:47 -0700
95
96  Briefly:
97    Morocco springs forward on 2020-05-31, not 2020-05-24.
98    Canada's Yukon advanced to -07 year-round on 2020-03-08.
99    America/Nuuk renamed from America/Godthab.
100    zic now supports expiration dates for leap second lists.
101
102  Changes to future timestamps
103
104    Morocco's second spring-forward transition in 2020 will be May 31,
105    not May 24 as predicted earlier.  (Thanks to Semlali Naoufal.)
106    Adjust future-year predictions to use the first Sunday after the
107    day after Ramadan, not the first Sunday after Ramadan.
108
109    Canada's Yukon, represented by America/Whitehorse and
110    America/Dawson, advanced to -07 year-round, beginning with its
111    spring-forward transition on 2020-03-08, and will not fall back on
112    2020-11-01.  Although a government press release calls this
113    "permanent Pacific Daylight Saving Time", we prefer MST for
114    consistency with nearby Dawson Creek, Creston, and Fort Nelson.
115    (Thanks to Tim Parenti.)
116
117  Changes to past timestamps
118
119    Shanghai observed DST in 1919.  (Thanks to Phake Nick.)
120
121  Changes to timezone identifiers
122
123    To reflect current usage in English better, America/Godthab has
124    been renamed to America/Nuuk.  A backwards-compatibility link
125    remains for the old name.
126
127  Changes to code
128
129    localtime.c no longer mishandles timestamps after the last
130    transition in a TZif file with leap seconds and with daylight
131    saving time transitions projected into the indefinite future.
132    For example, with TZ='America/Los_Angeles' with leap seconds,
133    zdump formerly reported a DST transition on 2038-03-14
134    from 01:59:32.999... to 02:59:33 instead of the correct transition
135    from 01:59:59.999... to 03:00:00.
136
137    zic -L now supports an Expires line in the leapseconds file, and
138    truncates the TZif output accordingly.  This propagates leap
139    second expiration information into the TZif file, and avoids the
140    abovementioned localtime.c bug as well as similar bugs present in
141    many client implementations.  If no Expires line is present, zic
142    -L instead truncates the TZif output based on the #expires comment
143    present in leapseconds files distributed by tzdb 2018f and later;
144    however, this usage is obsolescent.  For now, the distributed
145    leapseconds file has an Expires line that is commented out, so
146    that the file can be fed to older versions of zic which ignore the
147    commented-out line.  Future tzdb distributions are planned to
148    contain a leapseconds file with an Expires line.
149
150    The configuration macros HAVE_TZNAME and USG_COMPAT should now be
151    set to 1 if the system library supports the feature, and 2 if not.
152    As before, these macros are nonzero if tzcode should support the
153    feature, zero otherwise.
154
155    The configuration macro ALTZONE now has the same values with the
156    same meaning as HAVE_TZNAME and USG_COMPAT.
157
158    The code's defense against CRLF in leap-seconds.list is now
159    portable to POSIX awk.  (Problem reported by Deborah Goldsmith.)
160
161    Although the undocumented tzsetwall function is not changed in
162    this release, it is now deprecated in preparation for removal in
163    future releases.  Due to POSIX requirements, tzsetwall has not
164    worked for some time.  Any code that uses it should instead use
165    tzalloc(NULL) or, if portability trumps thread-safety, should
166    unset the TZ environment variable.
167
168  Changes to commentary
169
170    The Îles-de-la-Madeleine and the Listuguj reserve are noted as
171    following America/Halifax, and comments about Yukon's "south" and
172    "north" have been corrected to say "east" and "west".  (Thanks to
173    Jeffery Nichols.)
174
175
176Release 2019c - 2019-09-11 08:59:48 -0700
177
178  Briefly:
179    Fiji observes DST from 2019-11-10 to 2020-01-12.
180    Norfolk Island starts observing Australian-style DST.
181
182  Changes to future timestamps
183
184    Fiji's next DST transitions will be 2019-11-10 and 2020-01-12
185    instead of 2019-11-03 and 2020-01-19.  (Thanks to Raymond Kumar.)
186    Adjust future guesses accordingly.
187
188    Norfolk Island will observe Australian-style DST starting in
189    spring 2019.  The first transition is on 2019-10-06.  (Thanks to
190    Kyle Czech and Michael Deckers.)
191
192  Changes to past timestamps
193
194    Many corrections to time in Turkey from 1940 through 1985.
195    (Thanks to Oya Vulaş via Alois Treindl, and to Kıvanç Yazan.)
196
197    The Norfolk Island 1975-03-02 transition was at 02:00 standard
198    time, not 02:00 DST.  (Thanks to Michael Deckers.)
199
200    South Korea observed DST from 1948 through 1951.  Although this
201    info was supposed to appear in release 2014j, a typo inadvertently
202    suppressed the change.  (Thanks to Alois Treindl.)
203
204    Detroit observed DST in 1967 and 1968 following the US DST rules,
205    except that its 1967 DST began on June 14 at 00:01.  (Thanks to
206    Alois Treindl for pointing out that the old data entries were
207    probably wrong.)
208
209    Fix several errors in pre-1970 transitions in Perry County, IN.
210    (Thanks to Alois Triendl for pointing out the 1967/9 errors.)
211
212    Edmonton did not observe DST in 1967 or 1969.  In 1946 Vancouver
213    ended DST on 09-29 not 10-13, and Vienna ended DST on 10-07 not
214    10-06.  In 1945 Königsberg (now Kaliningrad) switched from +01/+02
215    to +02/+03 on 04-10 not 01-01, and its +02/+03 is abbreviated
216    EET/EEST, not CET/CEST.  (Thanks to Alois Triendl.)  In 1946
217    Königsberg switched to +03 on 04-07 not 01-01.
218
219    In 1946 Louisville switched from CST to CDT on 04-28 at 00:01, not
220    01-01 at 00:00.  (Thanks to Alois Treindl and Michael Deckers.)
221    Also, it switched from CST to CDT on 1950-04-30, not 1947-04-27.
222
223    The 1892-05-01 transition in Brussels was at 00:17:30, not at noon.
224    (Thanks to Michael Deckers.)
225
226  Changes to past time zone abbreviations and DST flags
227
228    Hong Kong Winter Time, observed from 1941-10-01 to 1941-12-25,
229    is now flagged as DST and is abbreviated HKWT not HKT.
230
231  Changes to code
232
233    leapseconds.awk now relies only on its input data, rather than
234    also relying on its comments.  (Inspired by code from Dennis
235    Ferguson and Chris Woodbury.)
236
237    The code now defends against CRLFs in leap-seconds.list.
238    (Thanks to Brian Inglis and Chris Woodbury.)
239
240  Changes to documentation and commentary
241
242    theory.html discusses leap seconds.  (Thanks to Steve Summit.)
243
244    Nashville's newspapers dueled about the time of day in the 1950s.
245    (Thanks to John Seigenthaler.)
246
247    Liechtenstein observed Swiss DST in 1941/2.
248    (Thanks to Alois Treindl.)
249
250
251Release 2019b - 2019-07-01 00:09:53 -0700
252
253  Briefly:
254    Brazil no longer observes DST.
255    'zic -b slim' outputs smaller TZif files; please try it out.
256    Palestine's 2019 spring-forward transition was on 03-29, not 03-30.
257
258  Changes to future timestamps
259
260    Brazil has canceled DST and will stay on standard time indefinitely.
261    (Thanks to Steffen Thorsen, Marcus Diniz, and Daniel Soares de
262    Oliveira.)
263
264    Predictions for Morocco now go through 2087 instead of 2037, to
265    work around a problem on newlib when using TZif files output by
266    zic 2019a or earlier.  (Problem reported by David Gauchard.)
267
268  Changes to past and future timestamps
269
270    Palestine's 2019 spring transition was 03-29 at 00:00, not 03-30
271    at 01:00.  (Thanks to Sharef Mustafa and Even Scharning.)  Guess
272    future transitions to be March's last Friday at 00:00.
273
274  Changes to past timestamps
275
276    Hong Kong's 1941-06-15 spring-forward transition was at 03:00, not
277    03:30.  Its 1945 transition from JST to HKT was on 11-18 at 02:00,
278    not 09-15 at 00:00.  In 1946 its spring-forward transition was on
279    04-21 at 00:00, not the previous day at 03:30.  From 1946 through
280    1952 its fall-back transitions occurred at 04:30, not at 03:30.
281    In 1947 its fall-back transition was on 11-30, not 12-30.
282    (Thanks to P Chan.)
283
284  Changes to past time zone abbreviations
285
286    Italy's 1866 transition to Rome Mean Time was on December 12, not
287    September 22.  This affects only the time zone abbreviation for
288    Europe/Rome between those dates.  (Thanks to Stephen Trainor and
289    Luigi Rosa.)
290
291  Changes affecting metadata only
292
293    Add info about the Crimea situation in zone1970.tab and zone.tab.
294    (Problem reported by Serhii Demediuk.)
295
296  Changes to code
297
298    zic's new -b option supports a way to control data bloat and to
299    test for year-2038 bugs in software that reads TZif files.
300    'zic -b fat' and 'zic -b slim' generate larger and smaller output;
301    for example, changing from fat to slim shrinks the Europe/London
302    file from 3648 to 1599 bytes, saving about 56%.  Fat and slim
303    files represent the same set of timestamps and use the same TZif
304    format as documented in tzfile(5) and in Internet RFC 8536.
305    Fat format attempts to work around bugs or incompatibilities in
306    older software, notably software that mishandles 64-bit TZif data
307    or uses obsolete TZ strings like "EET-2EEST" that lack DST rules.
308    Slim format is more efficient and does not work around 64-bit bugs
309    or obsolete TZ strings.  Currently zic defaults to fat format
310    unless you compile with -DZIC_BLOAT_DEFAULT=\"slim\"; this
311    out-of-the-box default is intended to change in future releases
312    as the buggy software often mishandles timestamps anyway.
313
314    zic no longer treats a set of rules ending in 2037 specially.
315    Previously, zic assumed that such a ruleset meant that future
316    timestamps could not be predicted, and therefore omitted a
317    POSIX-like TZ string in the TZif output.  The old behavior is no
318    longer needed for current tzdata, and caused problems with newlib
319    when used with older tzdata (reported by David Gauchard).
320
321    zic no longer generates some artifact transitions.  For example,
322    Europe/London no longer has a no-op transition in January 1996.
323
324  Changes to build procedure
325
326    tzdata.zi now assumes zic 2017c or later.  This shrinks tzdata.zi
327    by a percent or so.
328
329  Changes to documentation and commentary
330
331    The Makefile now documents the POSIXRULES macro as being obsolete,
332    and similarly, zic's -p POSIXRULES option is now documented as
333    being obsolete.  Although the POSIXRULES feature still exists and
334    works as before, in practice it is rarely used for its intended
335    purpose, and it does not work either in the default reference
336    implementation (for timestamps after 2037) or in common
337    implementations such as GNU/Linux (for contemporary timestamps).
338    Since POSIXRULES was designed primarily as a temporary transition
339    facility for System V platforms that died off decades ago, it is
340    being decommissioned rather than institutionalized.
341
342    New info on Bonin Islands and Marcus (thanks to Wakaba and Phake Nick).
343
344
345Release 2019a - 2019-03-25 22:01:33 -0700
346
347  Briefly:
348    Palestine "springs forward" on 2019-03-30 instead of 2019-03-23.
349    Metlakatla "fell back" to rejoin Alaska Time on 2019-01-20 at 02:00.
350
351  Changes to past and future timestamps
352
353    Palestine will not start DST until 2019-03-30, instead of 2019-03-23 as
354    previously predicted.  Adjust our prediction by guessing that spring
355    transitions will be between 24 and 30 March, which matches recent practice
356    since 2016.  (Thanks to Even Scharning and Tim Parenti.)
357
358    Metlakatla ended its observance of Pacific standard time,
359    rejoining Alaska Time, on 2019-01-20 at 02:00.  (Thanks to Ryan
360    Stanley and Tim Parenti.)
361
362  Changes to past timestamps
363
364    Israel observed DST in 1980 (08-02/09-13) and 1984 (05-05/08-25).
365    (Thanks to Alois Treindl and Isaac Starkman.)
366
367  Changes to time zone abbreviations
368
369    Etc/UCT is now a backward-compatibility link to Etc/UTC, instead
370    of being a separate zone that generates the abbreviation "UCT",
371    which nowadays is typically a typo.  (Problem reported by Isiah
372    Meadows.)
373
374  Changes to code
375
376    zic now has an -r option to limit the time range of output data.
377    For example, 'zic -r @1000000000' limits the output data to
378    timestamps starting 1000000000 seconds after the Epoch.
379    This helps shrink output size and can be useful for applications
380    not needing the full timestamp history, such as TZDIST truncation;
381    see Internet RFC 8536 section 5.1.  (Inspired by a feature request
382    from Christopher Wong, helped along by bug reports from Wong and
383    from Tim Parenti.)
384
385  Changes to documentation
386
387    Mention Internet RFC 8536 (February 2019), which documents TZif.
388
389    tz-link.html now cites tzdata-meta
390    <https://tzdata-meta.timtimeonline.com/>.
391
392
393Release 2018i - 2018-12-30 11:05:43 -0800
394
395  Briefly:
396    São Tomé and Príncipe switches from +01 to +00 on 2019-01-01.
397
398  Changes to future timestamps
399
400    Due to a change in government, São Tomé and Príncipe switches back
401    from +01 to +00 on 2019-01-01 at 02:00.  (Thanks to Vadim
402    Nasardinov and Michael Deckers.)
403
404
405Release 2018h - 2018-12-23 17:59:32 -0800
406
407  Briefly:
408    Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21.
409    New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move.
410    Metlakatla, Alaska observes PST this winter only.
411    Guess Morocco will continue to adjust clocks around Ramadan.
412    Add predictions for Iran from 2038 through 2090.
413
414  Changes to future timestamps
415
416    Guess that Morocco will continue to fall back just before and
417    spring forward just after Ramadan, the practice since 2012.
418    (Thanks to Maamar Abdelkader.)  This means Morocco will observe
419    negative DST during Ramadan in main and vanguard formats, and in
420    rearguard format it stays in the +00 timezone and observes
421    ordinary DST in all months other than Ramadan.  As before, extend
422    this guesswork to the year 2037.  As a consequence, Morocco is
423    scheduled to observe three DST transitions in some Gregorian years
424    (e.g., 2033) due to the mismatch between the Gregorian and Islamic
425    calendars.
426
427    The table of exact transitions for Iranian DST has been extended.
428    It formerly cut off before the year 2038 in a nod to 32-bit time_t.
429    It now cuts off before 2091 as there is doubt about how the Persian
430    calendar will treat 2091.  This change predicts DST transitions in
431    2038-9, 2042-3, and 2046-7 to occur one day later than previously
432    predicted.  As before, post-cutoff transitions are approximated.
433
434  Changes to past and future timestamps
435
436    Qyzylorda (aka Kyzylorda) oblast in Kazakhstan moved from +06 to
437    +05 on 2018-12-21.  This is a zone split as Qostanay (aka
438    Kostanay) did not switch, so create a zone Asia/Qostanay.
439
440    Metlakatla moved from Alaska to Pacific standard time on 2018-11-04.
441    It did not change clocks that day and remains on -08 this winter.
442    (Thanks to Ryan Stanley.)  It will revert to the usual Alaska
443    rules next spring, so this change affects only timestamps
444    from 2018-11-04 through 2019-03-10.
445
446  Change to past timestamps
447
448    Kwajalein's 1993-08-20 transition from -12 to +12 was at 24:00,
449    not 00:00.  I transcribed the time incorrectly from Shanks.
450    (Thanks to Phake Nick.)
451
452    Nauru's 1979 transition was on 02-10 at 02:00, not 05-01 at 00:00.
453    (Thanks to Phake Nick.)
454
455    Guam observed DST irregularly from 1959 through 1977.
456    (Thanks to Phake Nick.)
457
458    Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on
459    10-01 changed standard time to +08:30 (not +08).  Its transition
460    back to +08 after WWII was on 1945-09-15, not the previous day.
461    Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT).
462    (Thanks to Phake Nick, Steve Allen, and Joseph Myers.)  Also,
463    its 1952 fallback was on 11-02 (not 10-25).
464
465    This release contains many changes to timestamps before 1946 due
466    to Japanese possession or occupation of Pacific/Chuuk,
467    Pacific/Guam, Pacific/Kosrae, Pacific/Kwajalein, Pacific/Majuro,
468    Pacific/Nauru, Pacific/Palau, and Pacific/Pohnpei.
469    (Thanks to Phake Nick.)
470
471    Assume that the Spanish East Indies was like the Philippines and
472    observed American time until the end of 1844.  This affects
473    Pacific/Chuuk, Pacific/Kosrae, Pacific/Palau, and Pacific/Pohnpei.
474
475  Changes to past tm_isdst flags
476
477    For the recent Morocco change, the tm_isdst flag should be 1 from
478    2018-10-27 00:00 to 2018-10-28 03:00.  (Thanks to Michael Deckers.)
479    Give a URL to the official decree.  (Thanks to Matt Johnson.)
480
481
482Release 2018g - 2018-10-26 22:22:45 -0700
483
484  Briefly:
485    Morocco switches to permanent +01 on 2018-10-28.
486
487  Changes to future timestamps
488
489    Morocco switches from +00/+01 to permanent +01 effective 2018-10-28,
490    so its clocks will not fall back as previously scheduled.
491    (Thanks to Mohamed Essedik Najd and Brian Inglis.)
492
493  Changes to code
494
495    When generating TZif files with leap seconds, zic no longer uses a
496    format that trips up older 32-bit clients, fixing a bug introduced
497    in 2018f.  (Reported by Daniel Fischer.)  Also, the zic workaround
498    for QTBUG-53071 now also works for TZif files with leap seconds.
499
500    The translator to rearguard format now rewrites the line
501    "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to
502    "Rule Japan 1948 1951 - Sep Sun>=9  1:00 0 S".
503    This caters to zic before 2007 and to Oracle TZUpdater 2.2.0
504    and earlier.  (Reported by Christos Zoulas.)
505
506  Changes to past time zone abbreviations
507
508    Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii.
509    This reverts to 2011h, as the abbreviation change in 2011i was
510    likely inadvertent.
511
512  Changes to documentation
513
514    tzfile.5 has new sections on interoperability issues.
515
516
517Release 2018f - 2018-10-18 00:14:18 -0700
518
519  Briefly:
520  Volgograd moves from +03 to +04 on 2018-10-28.
521  Fiji ends DST 2019-01-13, not 2019-01-20.
522  Most of Chile changes DST dates, effective 2019-04-06.
523
524  Changes to future timestamps
525
526    Volgograd moves from +03 to +04 on 2018-10-28 at 02:00.
527    (Thanks to Alexander Fetisov and Stepan Golosunov.)
528
529    Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously
530    predicted.  (Thanks to Raymond Kumar.)  Adjust future predictions
531    accordingly.
532
533    Most of Chile will end DST on the first Saturday in April at 24:00 mainland
534    time, and resume DST on the first Saturday in September at 24:00 mainland
535    time.  The changes are effective from 2019-04-06, and do not affect the
536    Magallanes region modeled by America/Punta_Arenas.  (Thanks to Juan Correa
537    and Tim Parenti.)  Adjust future predictions accordingly.
538
539  Changes to past timestamps
540
541    The 2018-05-05 North Korea 30-minute time zone change took place
542    at 23:30 the previous day, not at 00:00 that day.
543
544    China's 1988 spring-forward transition was on April 17, not
545    April 10.  Its DST transitions in 1986/91 were at 02:00, not 00:00.
546    (Thanks to P Chan.)
547
548    Fix several issues for Macau before 1992.  Macau's pre-1904 LMT
549    was off by 10 s.  Macau switched to +08 in 1904 not 1912, and
550    temporarily switched to +09/+10 during World War II.  Macau
551    observed DST in 1942/79, not 1961/80, and there were several
552    errors for transition times and dates.  (Thanks to P Chan.)
553
554    The 1948-1951 fallback transitions in Japan were at 25:00 on
555    September's second Saturday, not at 24:00.  (Thanks to Phake Nick.)
556    zic turns this into 01:00 on the day after September's second
557    Saturday, which is the best that POSIX or C platforms can do.
558
559    Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014
560    paper by Li Yu, replacing more-questionable data from Shanks.
561
562  Changes to time zone abbreviations
563
564    Use "PST" and "PDT" for Philippine time.  (Thanks to Paul Goyette.)
565
566  Changes to code
567
568    zic now always generates TZif files where time type 0 is used for
569    timestamps before the first transition.  This simplifies the
570    reading of TZif files and should not affect behavior of existing
571    TZif readers because the same set of time types is used; only
572    their internal indexes may have changed.  This affects only the
573    legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
574    EET, which previously used nonzero types for these timestamps.
575
576    Because of the type 0 change, zic no longer outputs a dummy
577    transition at time -2**59 (before the Big Bang), as clients should
578    no longer need this to handle historical timestamps correctly.
579    This reverts a change introduced in 2013d and shrinks most TZif
580    files by a few bytes.
581
582    zic now supports negative time-of-day in Rule and Leap lines, e.g.,
583    "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
584    occurs at 18:00 on the Saturday before the last Sunday in April.
585    This behavior was documented in 2018a but the code did not
586    entirely match the documentation.
587
588    localtime.c no longer requires at least one time type in TZif
589    files that lack transitions or have a POSIX-style TZ string.  This
590    future-proofs the code against possible future extensions to the
591    format that would allow TZif files with POSIX-style TZ strings and
592    without transitions or time types.
593
594    A read-access subscript error in localtime.c has been fixed.
595    It could occur only in TZif files with timecnt == 0, something that
596    does not happen in practice now but could happen in future versions.
597
598    localtime.c no longer ignores TZif POSIX-style TZ strings that
599    specify only standard time.  Instead, these TZ strings now
600    override the default time type for timestamps after the last
601    transition (or for all timestamps if there are no transitions),
602    just as DST strings specifying DST have always done.
603
604    leapseconds.awk now outputs "#updated" and "#expires" comments,
605    and supports leap seconds at the ends of months other than June
606    and December.  (Inspired by suggestions from Chris Woodbury.)
607
608  Changes to documentation
609
610    New restrictions: A Rule name must start with a character that
611    is neither an ASCII digit nor "-" nor "+", and an unquoted name
612    should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
613    The latter restriction makes room for future extensions (a
614    possibility noted by Tom Lane).
615
616    tzfile.5 now documents what time types apply before the first and
617    after the last transition, if any.
618
619    Documentation now uses the spelling "timezone" for a TZ setting
620    that determines timestamp history, and "time zone" for a
621    geographic region currently sharing the same standard time.
622
623    The name "TZif" is now used for the tz binary data format.
624
625    tz-link.htm now mentions the A0 TimeZone Migration utilities.
626    (Thanks to Aldrin Martoq for the link.)
627
628  Changes to build procedure
629
630    New 'make' target 'rearguard_tarballs' to build the rearguard
631    tarball only.  This is a convenience on platforms that lack lzip
632    if you want to build the rearguard tarball.  (Problem reported by
633    Deborah Goldsmith.)
634
635    tzdata.zi is now more stable from release to release.  (Problem
636    noted by Tom Lane.)  It is also a bit shorter.
637
638    tzdata.zi now can contain comment lines documenting configuration
639    information, such as which data format was selected, which input
640    files were used, and how leap seconds are treated.  (Problems
641    noted by Lester Caine and Brian Inglis.)  If the Makefile defaults
642    are used these comment lines are absent, for backward
643    compatibility.  A redistributor intending to alter its copy of the
644    files should also append "-LABEL" to the 'version' file's first
645    line, where "LABEL" identifies the redistributor's change.
646
647
648Release 2018e - 2018-05-01 23:42:51 -0700
649
650  Briefly:
651
652    North Korea switches back to +09 on 2018-05-05.
653    The main format uses negative DST again, for Ireland etc.
654    'make tarballs' now also builds a rearguard tarball.
655    New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines.
656
657  Changes to past and future timestamps
658
659    North Korea switches back from +0830 to +09 on 2018-05-05.
660    (Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon,
661    and Tim Parenti.)
662
663    Bring back the negative-DST changes of 2018a, except be more
664    compatible with data parsers that do not support negative DST.
665    Also, this now affects historical timestamps in Namibia and the
666    former Czechoslovakia, not just Ireland.  The main format now uses
667    negative DST to model timestamps in Europe/Dublin (from 1971 on),
668    Europe/Prague (1946/7), and Africa/Windhoek (1994/2017).  This
669    does not affect UT offsets, only time zone abbreviations and the
670    tm_isdst flag.  Also, this does not affect rearguard or vanguard
671    formats; effectively the main format now uses vanguard instead of
672    rearguard format.  Data parsers that do not support negative DST
673    can still use data from the rearguard tarball described below.
674
675  Changes to build procedure
676
677    The command 'make tarballs' now also builds the tarball
678    tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz
679    except that it uses rearguard format intended for trailing-edge
680    data parsers.
681
682  Changes to data format and to code
683
684    The SAVE column of Rule and Zone lines can now have an 's' or 'd'
685    suffix, which specifies whether the adjusted time is standard time
686    or daylight saving time.  If no suffix is given, daylight saving
687    time is used if and only if the SAVE column is nonzero; this is
688    the longstanding behavior.  Although this new feature is not used
689    in tzdata, it could be used to specify the legal time in Namibia
690    1994-2017, as opposed to the popular time (see below).
691
692  Changes to past timestamps
693
694    From 1994 through 2017 Namibia observed DST in winter, not summer.
695    That is, it used negative DST, as Ireland still does.  This change
696    does not affect UTC offsets; it affects only the tm_isdst flag and
697    the abbreviation used during summer, which is now CAT, not WAST.
698    Although (as noted by Michael Deckers) summer and winter time were
699    both simply called "standard time" in Namibian law, in common
700    practice winter time was considered to be DST (as noted by Stephen
701    Colebourne).  The full effect of this change is only in vanguard
702    and main format; in rearguard format, the tm_isdst flag is still
703    zero in winter and nonzero in summer.
704
705    In 1946/7 Czechoslovakia also observed negative DST in winter.
706    The full effect of this change is only in vanguard and main
707    formats; in rearguard format, it is modeled as plain GMT without
708    daylight saving.  Also, the dates of some 1944/5 DST transitions
709    in Czechoslovakia have been changed.
710
711
712Release 2018d - 2018-03-22 07:05:46 -0700
713
714  Briefly:
715
716  Palestine starts DST a week earlier in 2018.
717  Add support for vanguard and rearguard data consumers.
718  Add subsecond precision to source data format, though not to data.
719
720  Changes to future timestamps
721
722    In 2018, Palestine starts DST on March 24, not March 31.
723    Adjust future predictions accordingly.  (Thanks to Sharef Mustafa.)
724
725  Changes to past and future timestamps
726
727    Casey Station in Antarctica changed from +11 to +08 on 2018-03-11
728    at 04:00.  (Thanks to Steffen Thorsen.)
729
730  Changes to past timestamps
731
732    Historical transitions for Uruguay, represented by
733    America/Montevideo, have been updated per official legal documents,
734    replacing previous data mainly originating from the inventions of
735    Shanks & Pottenger.  This has resulted in adjustments ranging from
736    30 to 90 minutes in either direction over at least two dozen
737    distinct periods ranging from one day to several years in length.
738    A mere handful of pre-1991 transitions are unaffected; data since
739    then has come from more reliable contemporaneous reporting.  These
740    changes affect various timestamps in 1920-1923, 1936, 1939,
741    1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990.
742    Additionally, Uruguay's pre-standard-time UT offset has been
743    adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to
744    match the location of the Observatory of the National Meteorological
745    Institute in Montevideo.
746    (Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.)
747
748    Enderbury and Kiritimati skipped New Year's Eve 1994, not
749    New Year's Day 1995.  (Thanks to Kerry Shetline.)
750
751    Fix the 1912-01-01 transition for Portugal and its colonies.
752    This transition was at 00:00 according to the new UT offset, not
753    according to the old one.  Also assume that Cape Verde switched on
754    the same date as the rest, not in 1907.  This affects
755    Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores,
756    Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon.
757    (Thanks to Michael Deckers.)
758
759    Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in
760    Turks & Caicos.
761
762  Changes to past time zone abbreviations
763
764    MMT took effect in Uruguay from 1908-06-10, not 1898-06-28.  There
765    is no clock change associated with the transition.
766
767  Changes to build procedure
768
769    The new DATAFORM macro in the Makefile lets the installer choose
770    among three source data formats.  The idea is to lessen downstream
771    disruption when data formats are improved.
772
773    * DATAFORM=vanguard installs from the latest, bleeding-edge
774      format.  DATAFORM=main (the default) installs from the format
775      used in the 'africa' etc. files.  DATAFORM=rearguard installs
776      from a trailing-edge format.  Eventually, elements of today's
777      vanguard format should move to the main format, and similarly
778      the main format's features should eventually move to the
779      rearguard format.
780
781    * In the current version, the main and rearguard formats are
782      identical and match that of 2018c, so this change does not
783      affect default behavior.  The vanguard format currently contains
784      one feature not in the main format: negative SAVE values.  This
785      improves support for Ireland, which uses Irish Standard Time
786      (IST, UTC+01) in summer and GMT (UTC) in winter.  tzcode has
787      supported negative SAVE values for decades, and this feature
788      should move to the main format soon.  However, it will not move
789      to the rearguard format for quite some time because some
790      downstream parsers do not support it.
791
792    * The build procedure constructs three files vanguard.zi, main.zi,
793      and rearguard.zi, one for each format.  Although the files
794      represent essentially the same data, they may have minor
795      discrepancies that users are not likely to notice.  The files
796      are intended for downstream data consumers and are not
797      installed.  Zoneinfo parsers that do not support negative SAVE values
798      should start using rearguard.zi, so that they will be unaffected
799      when the negative-DST feature moves from vanguard to main.
800      Bleeding-edge Zoneinfo parsers that support the new features
801      already can use vanguard.zi; in this respect, current tzcode is
802      bleeding-edge.
803
804    The Makefile should now be safe for parallelized builds, and 'make
805    -j to2050new.tzs' is now much faster on a multiprocessor host
806    with GNU Make.
807
808    When built with -DSUPPRESS_TZDIR, the tzcode library no longer
809    prepends TZDIR/ to file names that do not begin with '/'.  This is
810    not recommended for general use, due to its security implications.
811    (From a suggestion by Manuela Friedrich.)
812
813  Changes to code
814
815    zic now accepts subsecond precision in expressions like
816    00:19:32.13, which is approximately the legal time of the
817    Netherlands from 1835 to 1937.  However, because it is
818    questionable whether the few recorded uses of non-integer offsets
819    had subsecond precision in practice, there are no plans for tzdata
820    to use this feature.  (Thanks to Steve Allen for pointing out
821    the limitations of historical data in this area.)
822
823    The code is a bit more portable to MS-Windows.  Installers can
824    compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that
825    reserve identifiers like 'localtime'.  (Thanks to Manuela
826    Friedrich.)
827
828  Changes to documentation and commentary
829
830    theory.html now outlines tzdb's extensions to POSIX's model for
831    civil time, and has a section "POSIX features no longer needed"
832    that lists POSIX API components that are now vestigial.
833    (From suggestions by Steve Summit.)  It also better distinguishes
834    time zones from tz regions.  (From a suggestion by Guy Harris.)
835
836    Commentary is now more consistent about using the phrase "daylight
837    saving time", to match the C name tm_isdst.  Daylight saving time
838    need not occur in summer, and need not have a positive offset from
839    standard time.
840
841    Commentary about historical transitions in Uruguay has been expanded
842    with links to many relevant legal documents.
843    (Thanks to Tim Parenti.)
844
845    Commentary now uses some non-ASCII characters with Unicode value
846    less than U+0100, as they can be useful and should work even with
847    older editors such as XEmacs.
848
849
850Release 2018c - 2018-01-22 23:00:44 -0800
851
852  Briefly:
853  Revert Irish changes that relied on negative SAVE values.
854
855  Changes to tm_isdst
856
857    Revert the 2018a change to Europe/Dublin.  As before, this change
858    does not affect UT offsets or abbreviations; it affects only
859    whether timestamps are considered to be standard time or
860    daylight-saving time, as expressed in the tm_isdst flag of C's
861    struct tm type.  This reversion is intended to be a temporary
862    workaround for problems discovered with downstream uses of
863    releases 2018a and 2018b, which implemented Irish time by using
864    negative SAVE values in the Eire rules of the 'europe' file.
865    Although negative SAVE values have been part of tzcode for many
866    years and are supported by many platforms, they were not
867    documented before 2018a and ICU and OpenJDK do not currently
868    support them.  A mechanism to export data to platforms lacking
869    support for negative DST is planned to be developed before the
870    change is reapplied.  (Problems reported by Deborah Goldsmith and
871    Stephen Colebourne.)
872
873  Changes to past timestamps
874
875    Japanese DST transitions (1948-1951) were Sundays at 00:00, not
876    Saturdays or Sundays at 02:00.  (Thanks to Takayuki Nikai.)
877
878  Changes to build procedure
879
880    The build procedure now works around mawk 1.3.3's lack of support
881    for character class expressions.  (Problem reported by Ohyama.)
882
883
884Release 2018b - 2018-01-17 23:24:48 -0800
885
886  Briefly:
887  Fix a packaging problem in tz2018a, which was missing 'pacificnew'.
888
889  Changes to build procedure
890
891    The distribution now contains the file 'pacificnew' again.
892    This file was inadvertantly omitted in the 2018a distribution.
893    (Problem reported by Matias Fonzo.)
894
895
896Release 2018a - 2018-01-12 22:29:21 -0800
897
898  Briefly:
899  São Tomé and Príncipe switched from +00 to +01.
900  Brazil's DST will now start on November's first Sunday.
901  Ireland's standard time is now in the summer, not the winter.
902  Use Debian-style installation locations, instead of 4.3BSD-style.
903  New zic option -t.
904
905  Changes to past and future timestamps
906
907    São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at
908    01:00.  (Thanks to Steffen Thorsen and Michael Deckers.)
909
910  Changes to future timestamps
911
912    Starting in 2018 southern Brazil will begin DST on November's
913    first Sunday instead of October's third Sunday.  (Thanks to
914    Steffen Thorsen.)
915
916  Changes to past timestamps
917
918    A discrepancy of 4 s in timestamps before 1931 in South Sudan has
919    been corrected.  The 'backzone' and 'zone.tab' files did not agree
920    with the 'africa' and 'zone1970.tab' files.  (Problem reported by
921    Michael Deckers.)
922
923    The abbreviation invented for Bolivia Summer Time (1931-2) is now
924    BST instead of BOST, to be more consistent with the convention
925    used for Latvian Summer Time (1918-9) and for British Summer Time.
926
927  Changes to tm_isdst
928
929    Change Europe/Dublin so that it observes Irish Standard Time (UT
930    +01) in summer and GMT (as negative daylight-saving) in winter,
931    instead of observing standard time (GMT) in winter and Irish
932    Summer Time (UT +01) in summer.  This change does not affect UT
933    offsets or abbreviations; it affects only whether timestamps are
934    considered to be standard time or daylight-saving time, as
935    expressed in the tm_isdst flag of C's struct tm type.
936    (Discrepancy noted by Derick Rethans.)
937
938  Changes to build procedure
939
940    The default installation locations have been changed to mostly
941    match Debian circa 2017, instead of being designed as an add-on to
942    4.3BSD circa 1986.  This affects the Makefile macros TOPDIR,
943    TZDIR, MANDIR, and LIBDIR.  New Makefile macros TZDEFAULT, USRDIR,
944    USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor
945    locations more precisely.  (This responds to suggestions from
946    Brian Inglis and from Steve Summit.)
947
948    The default installation procedure no longer creates the
949    backward-compatibility link US/Pacific-New, which causes
950    confusion during user setup (e.g., see Debian bug 815200).
951    Use 'make BACKWARD="backward pacificnew"' to create the link
952    anyway, for now.  Eventually we plan to remove the link entirely.
953
954    tzdata.zi now contains a version-number comment.
955    (Suggested by Tom Lane.)
956
957    The Makefile now quotes values like BACKWARD more carefully when
958    passing them to the shell.  (Problem reported by Zefram.)
959
960    Builders no longer need to specify -DHAVE_SNPRINTF on platforms
961    that have snprintf and use pre-C99 compilers.  (Problem reported
962    by Jon Skeet.)
963
964  Changes to code
965
966    zic has a new option -t FILE that specifies the location of the
967    file that determines local time when TZ is unset.  The default for
968    this location can be configured via the new TZDEFAULT makefile
969    macro, which defaults to /etc/localtime.
970
971    Diagnostics and commentary now distinguish UT from UTC more
972    carefully; see theory.html for more information about UT vs UTC.
973
974    zic has been ported to GCC 8's -Wstringop-truncation option.
975    (Problem reported by Martin Sebor.)
976
977  Changes to documentation and commentary
978
979    The zic man page now documents the longstanding behavior that
980    times and years can be out of the usual range, with negative times
981    counting backwards from midnight and with year 0 preceding year 1.
982    (Problem reported by Michael Deckers.)
983
984    The theory.html file now mentions the POSIX limit of six chars
985    per abbreviation, and lists alphabetic abbreviations used.
986
987    The files tz-art.htm and tz-link.htm have been renamed to
988    tz-art.html and tz-link.html, respectively, for consistency with
989    other file names and to simplify web server configuration.
990
991
992Release 2017c - 2017-10-20 14:49:34 -0700
993
994  Briefly:
995  Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
996  Fiji ends DST 2018-01-14, not 2018-01-21.
997  Namibia switches from +01/+02 to +02 on 2018-04-01.
998  Sudan switches from +03 to +02 on 2017-11-01.
999  Tonga likely switches from +13/+14 to +13 on 2017-11-05.
1000  Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
1001  A new file tzdata.zi now holds a small text copy of all data.
1002  The zic input format has been regularized slightly.
1003
1004  Changes to future timestamps
1005
1006    Northern Cyprus has decided to resume EU rules starting
1007    2017-10-29, thus reinstituting winter time.
1008
1009    Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously
1010    predicted.  (Thanks to Dominic Fok.)  Adjust future predictions
1011    accordingly.
1012
1013    Namibia will switch from +01 with DST to +02 all year on
1014    2017-09-03 at 02:00.  This affects UT offsets starting 2018-04-01
1015    at 02:00.  (Thanks to Steffen Thorsen.)
1016
1017    Sudan will switch from +03 to +02 on 2017-11-01.  (Thanks to Ahmed
1018    Atyya and Yahia Abdalla.)  South Sudan is not switching, so
1019    Africa/Juba is no longer a link to Africa/Khartoum.
1020
1021    Tonga has likely ended its experiment with DST, and will not
1022    adjust its clocks on 2017-11-05.  Although Tonga has not announced
1023    whether it will continue to observe DST, the IATA is assuming that
1024    it will not.  (Thanks to David Wade.)
1025
1026    Turks & Caicos will switch from -04 all year to -05 with US DST on
1027    2018-03-11 at 03:00.  This affects UT offsets starting 2018-11-04
1028    at 02:00.  (Thanks to Steffen Thorsen.)
1029
1030  Changes to past timestamps
1031
1032    Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03.
1033    (Thanks to Arthur David Olson.)
1034
1035    Detroit did not observe DST in 1967.
1036
1037    Use railway time for Asia/Kolkata before 1941, by switching to
1038    Madras local time (UT +052110) in 1870, then to IST (UT +0530) in
1039    1906.  Also, treat 1941-2's +0630 as DST, like 1942-5.
1040
1041    Europe/Dublin's 1946 and 1947 fallback transitions occurred at
1042    02:00 standard time, not 02:00 DST.  (Thanks to Michael Deckers.)
1043
1044    Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to
1045    American time in 1892, not 1879.  (Thanks to Michael Deckers.)
1046
1047    Adjust the 1867 transition in Alaska to better reflect the
1048    historical record, by changing it to occur on 1867-10-18 at 15:30
1049    Sitka time rather than at the start of 1867-10-17 local time.
1050    Although strictly speaking this is accurate only for Sitka,
1051    the rest of Alaska's blanks need to be filled in somehow.
1052
1053    Fix off-by-one errors in UT offsets for Adak and Nome before 1867.
1054    (Thanks to Michael Deckers.)
1055
1056    Add 7 s to the UT offset in Asia/Yangon before 1920.
1057
1058  Changes to zone names
1059
1060    Remove Canada/East-Saskatchewan from the 'backward' file, as it
1061    exceeded the 14-character limit and was an unused misnomer anyway.
1062
1063  Changes to build procedure
1064
1065    To support applications that prefer to read time zone data in text
1066    form, two zic input files tzdata.zi and leapseconds are now
1067    installed by default.  The commands 'zic tzdata.zi' and 'zic -L
1068    leapseconds tzdata.zi' can reproduce the tzdata binary files
1069    without and with leap seconds, respectively.  To prevent these two
1070    new files from being installed, use 'make TZDATA_TEXT=', and to
1071    suppress leap seconds from the tzdata text installation, use 'make
1072    TZDATA_TEXT=tzdata.zi'.
1073
1074    'make BACKWARD=' now suppresses backward-compatibility names
1075    like 'US/Pacific' that are defined in the 'backward' and
1076    'pacificnew' files.
1077
1078    'make check' now works on systems that lack a UTF-8 locale,
1079    or that lack the nsgmls program.  Set UTF8_LOCALE to configure
1080    the name of a UTF-8 locale, if you have one.
1081
1082    Y2K runtime checks are no longer enabled by default.  Add
1083    -DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of
1084    adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
1085    to disable them.  (New name suggested by Brian Inglis.)
1086
1087    The build procedure for zdump now works on AIX 7.1.
1088    (Problem reported by Kees Dekker.)
1089
1090  Changes to code
1091
1092    zic and the reference runtime now reject multiple leap seconds
1093    within 28 days of each other, or leap seconds before the Epoch.
1094    As a result, support for double leap seconds, which was
1095    obsolescent and undocumented, has been removed.  Double leap
1096    seconds were an error in the C89 standard; they have never existed
1097    in civil timekeeping.  (Thanks to Robert Elz and Bradley White for
1098    noticing glitches in the code that uncovered this problem.)
1099
1100    zic now warns about use of the obsolescent and undocumented -y
1101    option, and about use of the obsolescent TYPE field of Rule lines.
1102
1103    zic now allows unambiguous abbreviations like "Sa" and "Su" for
1104    weekdays; formerly it rejected them due to a bug.  Conversely, zic
1105    no longer considers non-prefixes to be abbreviations; for example,
1106    it no longer accepts "lF" as an abbreviation for "lastFriday".
1107    Also, zic warns about the undocumented usage with a "last-"
1108    prefix, e.g., "last-Fri".
1109
1110    Similarly, zic now accepts the unambiguous abbreviation "L" for
1111    "Link" in ordinary context and for "Leap" in leap-second context.
1112    Conversely, zic no longer accepts non-prefixes such as "La" as
1113    abbreviations for words like "Leap".
1114
1115    zic no longer accepts leap second lines in ordinary input, or
1116    ordinary lines in leap second input.  Formerly, zic sometimes
1117    warned about this undocumented usage and handled it incorrectly.
1118
1119    The new macro HAVE_TZNAME governs whether the tzname external
1120    variable is exported, instead of USG_COMPAT.  USG_COMPAT now
1121    governs only the external variables "timezone" and "daylight".
1122    This change is needed because the three variables are not in the
1123    same category: although POSIX requires tzname, it specifies the
1124    other two variables as optional.  Also, USG_COMPAT is now 1 or 0:
1125    if not defined, the code attempts to guess it from other macros.
1126
1127    localtime.c and difftime.c no longer require stdio.h, and .c files
1128    other than zic.c no longer require sys/wait.h.
1129
1130    zdump.c no longer assumes snprintf.  (Reported by Jonathan Leffler.)
1131
1132    Calculation of time_t extrema works around a bug in GCC 4.8.4
1133    (Reported by Stan Shebs and Joseph Myers.)
1134
1135    zic.c no longer mistranslates formats of line numbers in non-English
1136    locales.  (Problem reported by Benno Schulenberg.)
1137
1138    Several minor changes have been made to the code to make it a
1139    bit easier to port to MS-Windows and Solaris.  (Thanks to Kees
1140    Dekker for reporting the problems.)
1141
1142  Changes to documentation and commentary
1143
1144    The two new files 'theory.html' and 'calendars' contain the
1145    contents of the removed file 'Theory'.  The goal is to document
1146    tzdb theory more accessibly.
1147
1148    The zic man page now documents abbreviation rules.
1149
1150    tz-link.htm now covers how to apply tzdata changes to clients.
1151    (Thanks to Jorge Fábregas for the AIX link.)  It also mentions MySQL.
1152
1153    The leap-seconds.list URL has been updated to something that is
1154    more reliable for tzdb.  (Thanks to Tim Parenti and Brian Inglis.)
1155
1156Release 2017b - 2017-03-17 07:30:38 -0700
1157
1158  Briefly: Haiti has resumed DST.
1159
1160  Changes to past and future timestamps
1161
1162    Haiti resumed observance of DST in 2017.  (Thanks to Steffen Thorsen.)
1163
1164  Changes to past timestamps
1165
1166    Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.
1167
1168    Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
1169    is one byte over the POSIX limit.  (Problem reported by Derick Rethans.)
1170
1171  Changes to code
1172
1173    The reference localtime implementation now falls back on the
1174    current US daylight-saving transition rules rather than the
1175    1987-2006 rules.  This fallback occurs only when (1) the TZ
1176    environment variable has a value like "AST4ADT" that asks
1177    for daylight saving time but does not specify the rules, (2) there
1178    is no file by that name, and (3) the TZDEFRULES file cannot be
1179    loaded.  (Thanks to Tom Lane.)
1180
1181
1182Release 2017a - 2017-02-28 00:05:36 -0800
1183
1184  Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
1185  discontinues DST.
1186
1187  Changes to future timestamps
1188
1189    Mongolia no longer observes DST.  (Thanks to Ganbold Tsagaankhuu.)
1190
1191    Chile's Region of Magallanes moves from -04/-03 to -03 year-round.
1192    Its clocks diverge from America/Santiago starting 2017-05-13 at
1193    23:00, hiving off a new zone America/Punta_Arenas.  Although the
1194    Chilean government says this change expires in May 2019, for now
1195    assume it's permanent.  (Thanks to Juan Correa and Deborah
1196    Goldsmith.)  This also affects Antarctica/Palmer.
1197
1198  Changes to past timestamps
1199
1200    Fix many entries for historical timestamps for Europe/Madrid
1201    before 1979, to agree with tables compiled by Pere Planesas of the
1202    National Astronomical Observatory of Spain.  As a side effect,
1203    this changes some timestamps for Africa/Ceuta before 1929, which
1204    are probably guesswork anyway.  (Thanks to Steve Allen and
1205    Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for
1206    correcting the 1901 transition.)
1207
1208    Ecuador observed DST from 1992-11-28 to 1993-02-05.
1209    (Thanks to Alois Treindl.)
1210
1211    Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21.
1212    (Thanks to Stepan Golosunov.)
1213
1214  Changes to past and future time zone abbreviations
1215
1216    Switch to numeric time zone abbreviations for South America, as
1217    part of the ongoing project of removing invented abbreviations.
1218    This avoids the need to invent an abbreviation for the new Chilean
1219    new zone.  Similarly, switch from invented to numeric time zone
1220    abbreviations for Afghanistan, American Samoa, the Azores,
1221    Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei,
1222    Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is,
1223    Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland,
1224    Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia,
1225    the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia,
1226    Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau,
1227    Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St
1228    Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore,
1229    Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and
1230    Xinjiang; for 20-minute daylight saving time in Ghana before 1943;
1231    for half-hour daylight saving time in Belize before 1944 and in
1232    the Dominican Republic before 1975; and for Canary Islands before
1233    1946, for Guinea-Bissau before 1975, for Iceland before 1969, for
1234    Indian Summer Time before 1942, for Indonesia before around 1964,
1235    for Kenya before 1960, for Liberia before 1973, for Madeira before
1236    1967, for Namibia before 1943, for the Netherlands in 1937-9, for
1237    Pakistan before 1971, for Western Sahara before 1977, and for
1238    Zaporozhye in 1880-1924.
1239
1240    For Alaska time from 1900 through 1967, instead of "CAT" use the
1241    abbreviation "AST", the abbreviation commonly used at the time
1242    (Atlantic Standard Time had not been standardized yet).  Use "AWT"
1243    and "APT" instead of the invented abbreviations "CAWT" and "CAPT".
1244
1245    Use "CST" and "CDT" instead of invented abbreviations for Macau
1246    before 1999 and Taiwan before 1938, and use "JST" instead of the
1247    invented abbreviation "JCST" for Japan and Korea before 1938.
1248
1249  Change to database entry category
1250
1251    Move the Pacific/Johnston link from 'australasia' to 'backward',
1252    since Johnston is now uninhabited.
1253
1254  Changes to code
1255
1256    zic no longer mishandles some transitions in January 2038 when it
1257    attempts to work around Qt bug 53071.  This fixes a bug affecting
1258    Pacific/Tongatapu that was introduced in zic 2016e.  localtime.c
1259    now contains a workaround, useful when loading a file generated by
1260    a buggy zic.  (Problem and localtime.c fix reported by Bradley
1261    White.)
1262
1263    zdump -i now outputs non-hour numeric time zone abbreviations
1264    without a colon, e.g., "+0530" rather than "+05:30".  This agrees
1265    with zic %z and with common practice, and simplifies auditing of
1266    zdump output.
1267
1268    zdump is now buildable again with -DUSE_LTZ=0.
1269    (Problem reported by Joseph Myers.)
1270
1271    zdump.c now always includes private.h, to avoid code duplication
1272    with private.h.  (Problem reported by Kees Dekker.)
1273
1274    localtime.c no longer mishandles early or late timestamps
1275    when TZ is set to a POSIX-style string that specifies DST.
1276    (Problem reported by Kees Dekker.)
1277
1278    date and strftime now cause %z to generate "-0000" instead of
1279    "+0000" when the UT offset is zero and the time zone abbreviation
1280    begins with "-".
1281
1282  Changes to documentation and commentary
1283
1284    The 'Theory' file now better documents choice of historical time
1285    zone abbreviations.  (Problems reported by Michael Deckers.)
1286
1287    tz-link.htm now covers leap smearing, which is popular in clouds.
1288
1289
1290Release 2016j - 2016-11-22 23:17:13 -0800
1291
1292  Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.
1293
1294  Changes to future timestamps
1295
1296    Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00.
1297    This hives off a new zone Europe/Saratov from Europe/Volgograd.
1298    (Thanks to Yuri Konotopov and Stepan Golosunov.)
1299
1300  Changes to past timestamps
1301
1302    The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
1303    Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
1304    1999, not fall 1994.  (Thanks to Stepan Golosunov.)
1305
1306  Changes to past time zone abbreviations
1307
1308    Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote
1309    summer time before 1948.  The old use of "EET" was a typo.
1310
1311  Changes to code
1312
1313    zic no longer mishandles file systems that lack hard links, fixing
1314    bugs introduced in 2016g.  (Problems reported by Tom Lane.)
1315    Also, when the destination already contains symbolic links, zic
1316    should now work better on systems where the 'link' system call
1317    does not follow symbolic links.
1318
1319  Changes to documentation and commentary
1320
1321    tz-link.htm now documents the relationship between release version
1322    numbers and development-repository commit tags.  (Suggested by
1323    Paul Koning.)
1324
1325    The 'Theory' file now documents UT.
1326
1327    iso3166.tab now accents "Curaçao", and commentary now mentions
1328    the names "Cabo Verde" and "Czechia".  (Thanks to Jiří Boháč.)
1329
1330
1331Release 2016i - 2016-11-01 23:19:52 -0700
1332
1333  Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga
1334  reintroduces DST on 2016-11-06.
1335
1336  Changes to future timestamps
1337
1338    Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on
1339    2017-01-15 at 03:00.  Assume future observances in Tonga will be
1340    from the first Sunday in November through the third Sunday in
1341    January, like Fiji.  (Thanks to Pulu ʻAnau.)  Switch to numeric
1342    time zone abbreviations for this zone.
1343
1344  Changes to past and future timestamps
1345
1346    Northern Cyprus is now +03 year round, causing a split in Cyprus
1347    time zones starting 2016-10-30 at 04:00.  This creates a zone
1348    Asia/Famagusta.  (Thanks to Even Scharning and Matt Johnson.)
1349
1350    Antarctica/Casey switched from +08 to +11 on 2016-10-22.
1351    (Thanks to Steffen Thorsen.)
1352
1353  Changes to past timestamps
1354
1355    Several corrections were made for pre-1975 timestamps in Italy.
1356    These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and
1357    Europe/Vatican.
1358
1359    First, the 1893-11-01 00:00 transition in Italy used the new UT
1360    offset (+01), not the old (+00:49:56).  (Thanks to Michael
1361    Deckers.)
1362
1363    Second, rules for daylight saving in Italy were changed to agree
1364    with Italy's National Institute of Metrological Research (INRiM)
1365    except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian
1366    Inglis, and Michael Deckers):
1367
1368      The 1916-06-03 transition was at 24:00, not 00:00.
1369
1370      The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at
1371      00:00, not 01:00.
1372
1373      The 1917-09-30 and 1918-10-06 transitions were at 24:00, not
1374      01:00.
1375
1376      The 1944-09-17 transition was at 03:00, not 01:00.  This
1377      particular change is taken from Italian law as INRiM's table,
1378      (which says 02:00) appears to have a typo here.  Also, keep the
1379      1944-04-03 transition for Europe/Rome, as Rome was controlled by
1380      Germany then.
1381
1382      The 1967-1970 and 1972-1974 fallback transitions were at 01:00,
1383      not 00:00.
1384
1385  Changes to code
1386
1387    The code should now be buildable on AmigaOS merely by setting the
1388    appropriate Makefile variables.  (From a patch by Carsten Larsen.)
1389
1390
1391Release 2016h - 2016-10-19 23:17:57 -0700
1392
1393  Changes to future timestamps
1394
1395    Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not
1396    2016-10-21 at 00:00.  (Thanks to Sharef Mustafa.)  Predict that
1397    future fall transitions will be on the last Saturday of October
1398    at 01:00, which is consistent with predicted spring transitions
1399    on the last Saturday of March.  (Thanks to Tim Parenti.)
1400
1401  Changes to past timestamps
1402
1403    In Turkey, transitions in 1986-1990 were at 01:00 standard time
1404    not at 02:00, and the spring 1994 transition was on March 20, not
1405    March 27.  (Thanks to Kıvanç Yazan.)
1406
1407  Changes to past and future time zone abbreviations
1408
1409    Asia/Colombo now uses numeric time zone abbreviations like "+0530"
1410    instead of alphabetic ones like "IST" and "LKT".  Various
1411    English-language sources use "IST", "LKT" and "SLST", with no
1412    working consensus.  (Usage of "SLST" mentioned by Sadika
1413    Sumanapala.)
1414
1415  Changes to code
1416
1417    zic no longer mishandles relativizing file names when creating
1418    symbolic links like /etc/localtime, when these symbolic links
1419    are outside the usual directory hierarchy.  This fixes a bug
1420    introduced in 2016g.  (Problem reported by Andreas Stieger.)
1421
1422  Changes to build procedure
1423
1424    New rules 'traditional_tarballs' and 'traditional_signatures' for
1425    building just the traditional-format distribution.  (Requested by
1426    Deborah Goldsmith.)
1427
1428    The file 'version' is now put into the tzdata tarball too.
1429    (Requested by Howard Hinnant.)
1430
1431  Changes to documentation and commentary
1432
1433    The 'Theory' file now has a section on interface stability.
1434    (Requested by Paul Koning.)  It also mentions features like
1435    tm_zone and localtime_rz that have long been supported by the
1436    reference code.
1437
1438    tz-link.htm has improved coverage of time zone boundaries suitable
1439    for geolocation.  (Thanks to heads-ups from Evan Siroky and Matt
1440    Johnson.)
1441
1442    The US commentary now mentions Allen and the "day of two noons".
1443
1444    The Fiji commentary mentions the government's 2016-10-03 press
1445    release.  (Thanks to Raymond Kumar.)
1446
1447
1448Release 2016g - 2016-09-13 08:56:38 -0700
1449
1450  Changes to future timestamps
1451
1452    Turkey switched from EET/EEST (+02/+03) to permanent +03,
1453    effective 2016-09-07.  (Thanks to Burak AYDIN.)  Use "+03" rather
1454    than an invented abbreviation for the new time.
1455
1456    New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52.
1457    (Thanks to Tim Parenti.)
1458
1459  Changes to past timestamps
1460
1461    For America/Los_Angeles, spring-forward transition times have been
1462    corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in
1463    1950-1966.
1464
1465    For zones using Soviet time on 1919-07-01, transitions to UT-based
1466    time were at 00:00 UT, not at 02:00 local time.  The affected
1467    zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and
1468    Europe/Ulyanovsk.  (Thanks to Alexander Belopolsky.)
1469
1470  Changes to past and future time zone abbreviations
1471
1472    The Factory zone now uses the time zone abbreviation -00 instead
1473    of a long English-language string, as -00 is now the normal way to
1474    represent an undefined time zone.
1475
1476    Several zones in Antarctica and the former Soviet Union, along
1477    with zones intended for ships at sea that cannot use POSIX TZ
1478    strings, now use numeric time zone abbreviations instead of
1479    invented or obsolete alphanumeric abbreviations.  The affected
1480    zones are Antarctica/Casey, Antarctica/Davis,
1481    Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
1482    Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
1483    Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
1484    Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga,
1485    Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
1486    Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
1487    Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
1488    Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
1489    Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
1490    Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
1491    Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
1492    Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
1493    Europe/Minsk, Europe/Samara, Europe/Volgograd, and
1494    Indian/Kerguelen.  For Europe/Moscow the invented abbreviation MSM
1495    was replaced by +05, whereas MSK and MSD were kept as they are not
1496    our invention and are widely used.
1497
1498  Changes to zone names
1499
1500    Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link.
1501    (Thanks to David Massoud.)
1502
1503  Changes to code
1504
1505    zic no longer generates binary files containing POSIX TZ-like
1506    strings that disagree with the local time type after the last
1507    explicit transition in the data.  This fixes a bug with
1508    Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps
1509    on the reference platform.  (Thanks to Alexander Belopolsky for
1510    reporting the bug and suggesting a way forward.)
1511
1512    If the installed localtime and/or posixrules files are symbolic
1513    links, zic now keeps them symbolic links when updating them, for
1514    compatibility with platforms like OpenSUSE where other programs
1515    configure these files as symlinks.
1516
1517    zic now avoids hard linking to symbolic links, avoids some
1518    unnecessary mkdir and stat system calls, and uses shorter file
1519    names internally.
1520
1521    zdump has a new -i option to generate transitions in a
1522    more-compact but still human-readable format.  This option is
1523    experimental, and the output format may change in future versions.
1524    (Thanks to Jon Skeet for suggesting that an option was needed,
1525    and thanks to Tim Parenti and Chris Rovick for further comments.)
1526
1527  Changes to build procedure
1528
1529    An experimental distribution format is available, in addition
1530    to the traditional format which will continue to be distributed.
1531    The new format is a tarball tzdb-VERSION.tar.lz with signature
1532    file tzdb-VERSION.tar.lz.asc.  It unpacks to a top-level directory
1533    tzdb-VERSION containing the code and data of the traditional
1534    two-tarball format, along with extra data that may be useful.
1535    (Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others
1536    for comments about the experimental format.)
1537
1538    The release version number is now more accurate in the usual case
1539    where releases are built from a Git repository.  For example, if
1540    23 commits and some working-file changes have been made since
1541    release 2016g, the version number is now something like
1542    '2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
1543    Tagged releases use the same version number format as before,
1544    e.g., '2016g'.  To support the more-accurate version number, its
1545    specification has moved from a line in the Makefile to a new
1546    source file 'version'.
1547
1548    The experimental distribution contains a file to2050.tzs that
1549    contains what should be the output of 'zdump -i -c 2050' on
1550    primary zones.  If this file is available, 'make check' now checks
1551    that zdump generates this output.
1552
1553    'make check_web' now works on Fedora-like distributions.
1554
1555  Changes to documentation and commentary
1556
1557    tzfile.5 now documents the new restriction on POSIX TZ-like
1558    strings that is now implemented by zic.
1559
1560    Comments now cite URLs for some 1917-1921 Russian DST decrees.
1561    (Thanks to Alexander Belopolsky.)
1562
1563    tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J
1564    (thanks to Meno Hochschild) and ThreeTen-Extra, and its
1565    description of Java 8 has been brought up to date (thanks to
1566    Stephen Colebourne).  Its description of local time on Mars has
1567    been updated to match current practice, and URLs have been updated
1568    and some obsolete ones removed.
1569
1570
1571Release 2016f - 2016-07-05 16:26:51 +0200
1572
1573  Changes affecting future timestamps
1574
1575    The Egyptian government changed its mind on short notice, and
1576    Africa/Cairo will not introduce DST starting 2016-07-07 after all.
1577    (Thanks to Mina Samuel.)
1578
1579    Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00.
1580    (Thanks to Stepan Golosunov.)
1581
1582  Changes to past and future timestamps
1583
1584    Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone
1585    abbreviations instead of invented ones.
1586
1587  Changes affecting past timestamps
1588
1589    Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00.
1590    (Thanks to Stepan Golosunov.)
1591
1592
1593Release 2016e - 2016-06-14 08:46:16 -0700
1594
1595  Changes affecting future timestamps
1596
1597    Africa/Cairo observes DST in 2016 from July 7 to the end of October.
1598    Guess October 27 and 24:00 transitions.  (Thanks to Steffen Thorsen.)
1599    For future years, guess April's last Thursday to October's last
1600    Thursday except for Ramadan.
1601
1602  Changes affecting past timestamps
1603
1604    Locations while uninhabited now use '-00', not 'zzz', as a
1605    placeholder time zone abbreviation.  This is inspired by Internet
1606    RFC 3339 and is more consistent with numeric time zone
1607    abbreviations already used elsewhere.  The change affects several
1608    arctic and antarctic locations, e.g., America/Cambridge_Bay before
1609    1920 and Antarctica/Troll before 2005.
1610
1611    Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was
1612    at 03:00, not 23:00 the previous day.  (Thanks to Michael Deckers.)
1613
1614  Changes to code
1615
1616    zic now outputs a dummy transition at time 2**31 - 1 in zones
1617    whose POSIX-style TZ strings contain a '<'.  This mostly works
1618    around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>.
1619    (Thanks to Zhanibek Adilbekov for reporting the Qt bug.)
1620
1621  Changes affecting documentation and commentary
1622
1623    tz-link.htm says why governments should give plenty of notice for
1624    time zone or DST changes, and refers to Matt Johnson's blog post.
1625
1626    tz-link.htm mentions Tzdata for Elixir.  (Thanks to Matt Johnson.)
1627
1628
1629Release 2016d - 2016-04-17 22:50:29 -0700
1630
1631  Changes affecting future timestamps
1632
1633    America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30.
1634    (Thanks to Alexander Krivenyshev for the heads-up.)
1635
1636    Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00.
1637    (Thanks to Alexander Krivenyshev and Matt Johnson.)
1638
1639    New zone Asia/Tomsk, split off from Asia/Novosibirsk.  It covers
1640    Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29
1641    at 02:00.  (Thanks to Stepan Golosunov.)
1642
1643  Changes affecting past timestamps
1644
1645    New zone Europe/Kirov, split off from Europe/Volgograd.  It covers
1646    Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on
1647    1989-03-26 at 02:00, roughly a year after Europe/Volgograd made
1648    the same change.  (Thanks to Stepan Golosunov.)
1649
1650    Russia and nearby locations had daylight-saving transitions on
1651    1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on
1652    1992-03-28 at 23:00 and 1992-09-26 at 23:00.  (Thanks to Stepan
1653    Golosunov.)
1654
1655    Many corrections to historical time in Kazakhstan from 1991
1656    through 2005.  (Thanks to Stepan Golosunov.)  Replace Kazakhstan's
1657    invented time zone abbreviations with numeric abbreviations.
1658
1659  Changes to commentary
1660
1661    Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references).
1662
1663
1664Release 2016c - 2016-03-23 00:51:27 -0700
1665
1666  Changes affecting future timestamps
1667
1668    Azerbaijan no longer observes DST.  (Thanks to Steffen Thorsen.)
1669
1670    Chile reverts from permanent to seasonal DST.  (Thanks to Juan
1671    Correa for the heads-up, and to Tim Parenti for corrections.)
1672    Guess that future transitions are August's and May's second
1673    Saturdays at 24:00 mainland time.  Also, call the period from
1674    2014-09-07 through 2016-05-14 daylight saving time instead of
1675    standard time, as that seems more appropriate now.
1676
1677  Changes affecting past timestamps
1678
1679    Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to
1680    +02/+03 on 1989-03-26, not 1991-03-31.  Europe/Volgograd changed
1681    from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26.
1682    (Thanks to Stepan Golosunov.)
1683
1684  Changes to commentary
1685
1686    Several updates and URLs for historical and proposed Russian changes.
1687    (Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.)
1688
1689
1690Release 2016b - 2016-03-12 17:30:14 -0800
1691
1692  Compatibility note
1693
1694    Starting with release 2016b, some data entries cause zic implementations
1695    derived from tz releases 2005j through 2015e to issue warnings like
1696    "time zone abbreviation differs from POSIX standard (+03)".
1697    These warnings should not otherwise affect zic's output and can safely be
1698    ignored on today's platforms, as the warnings refer to a restriction in
1699    POSIX.1-1988 that was removed in POSIX.1-2001.  One way to suppress the
1700    warnings is to upgrade to zic derived from tz releases 2015f and later.
1701
1702  Changes affecting future timestamps
1703
1704    New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and
1705    Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on
1706    2016-03-27 at 02:00 local time.  They need distinct zones since their
1707    post-1970 histories disagree.  New zone Asia/Barnaul for Altai Krai and
1708    Altai Republic, Russia, which will switch from +06 to +07 on the same date
1709    and local time.  The Astrakhan change is already official; the others have
1710    passed the first reading in the State Duma and are extremely likely.
1711    Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00.
1712    (Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson
1713    and Stepan Golosunov for followup.)
1714
1715    As a trial of a new system that needs less information to be made up,
1716    the new zones use numeric time zone abbreviations like "+04"
1717    instead of invented abbreviations like "ASTT".
1718
1719    Haiti will not observe DST in 2016.  (Thanks to Jean Antoine via
1720    Steffen Thorsen.)
1721
1722    Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00.
1723    (Thanks to Hannah Kreitem.) Guess future transitions will be March's last
1724    Saturday at 01:00, not March's last Friday at 24:00.
1725
1726  Changes affecting past timestamps
1727
1728    Europe/Chisinau observed DST during 1990, and switched from +04 to
1729    +03 at 1990-05-06 02:00, instead of switching from +03 to +02.
1730    (Thanks to Stepan Golosunov.)
1731
1732    1991 abbreviations in Europe/Samara should be SAMT/SAMST, not
1733    KUYT/KUYST.  (Thanks to Stepan Golosunov.)
1734
1735  Changes to code
1736
1737    tzselect's diagnostics and checking, and checktab.awk's checking,
1738    have been improved.  (Thanks to J William Piggott.)
1739
1740    tzcode now builds under MinGW.  (Thanks to Ian Abbott and Esben Haabendal.)
1741
1742    tzselect now tests Julian-date TZ settings more accurately.
1743    (Thanks to J William Piggott.)
1744
1745  Changes to commentary
1746
1747    Comments in zone tables have been improved.  (Thanks to J William Piggott.)
1748
1749    tzselect again limits its menu comments so that menus fit on a
1750    24×80 alphanumeric display.
1751
1752    A new web page tz-how-to.html.  (Thanks to Bill Seymour.)
1753
1754    In the Theory file, the description of possible time zone abbreviations in
1755    tzdata has been cleaned up, as the old description was unclear and
1756    inconsistent.  (Thanks to Alain Mouette for reporting the problem.)
1757
1758
1759Release 2016a - 2016-01-26 23:28:02 -0800
1760
1761  Changes affecting future timestamps
1762
1763    America/Cayman will not observe daylight saving this year after all.
1764    Revert our guess that it would.  (Thanks to Matt Johnson.)
1765
1766    Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00.
1767    (Thanks to Alexander Krivenyshev.)
1768
1769    Asia/Tehran now has DST predictions for the year 2038 and later,
1770    to be March 21 00:00 to September 21 00:00.  This is likely better
1771    than predicting no DST, albeit off by a day every now and then.
1772
1773  Changes affecting past and future timestamps
1774
1775    America/Metlakatla switched from PST all year to AKST/AKDT on
1776    2015-11-01 at 02:00.  (Thanks to Steffen Thorsen.)
1777
1778    America/Santa_Isabel has been removed, and replaced with a
1779    backward compatibility link to America/Tijuana.  Its contents were
1780    apparently based on a misreading of Mexican legislation.
1781
1782  Changes affecting past timestamps
1783
1784    Asia/Karachi's two transition times in 2002 were off by a minute.
1785    (Thanks to Matt Johnson.)
1786
1787  Changes affecting build procedure
1788
1789    An installer can now combine leap seconds with use of the backzone file,
1790    e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'.
1791    The old 'make posix_packrat' rule is now marked as obsolescent.
1792    (Thanks to Ian Abbott for an initial implementation.)
1793
1794  Changes affecting documentation and commentary
1795
1796    A new file LICENSE makes it easier to see that the code and data
1797    are mostly public-domain.  (Thanks to James Knight.)  The three
1798    non-public-domain files now use the current (3-clause) BSD license
1799    instead of older versions of that license.
1800
1801    tz-link.htm mentions the BDE library (thanks to Andrew Paprocki),
1802    CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section
1803    on editing tz source files (with a mention of Sublime zoneinfo,
1804    thanks to Gilmore Davidson).
1805
1806    The Theory and asia files now mention the 2015 book "The Global
1807    Transformation of Time, 1870-1950", and cite a couple of reviews.
1808
1809    The America/Chicago entry now documents the informal use of US
1810    central time in Fort Pierre, South Dakota.  (Thanks to Rick
1811    McDermid, Matt Johnson, and Steve Jones.)
1812
1813
1814Release 2015g - 2015-10-01 00:39:51 -0700
1815
1816  Changes affecting future timestamps
1817
1818    Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25.
1819    (Thanks to Fatih.)
1820
1821    Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time.
1822    (Thanks to Alexander Krivenyshev.)
1823
1824    Fiji's 2016 fall-back transition is scheduled for January 17, not 24.
1825    (Thanks to Ken Rylander.)
1826
1827    Fort Nelson, British Columbia will not fall back on 2015-11-01.  It has
1828    effectively been on MST (-0700) since it advanced its clocks on 2015-03-08.
1829    New zone America/Fort_Nelson.  (Thanks to Matt Johnson.)
1830
1831  Changes affecting past timestamps
1832
1833    Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00.
1834
1835  Changes affecting code
1836
1837    localtime no longer mishandles America/Anchorage after 2037.
1838    (Thanks to Bradley White for reporting the bug.)
1839
1840    On hosts with signed 32-bit time_t, localtime no longer mishandles
1841    Pacific/Fiji after 2038-01-16 14:00 UTC.
1842
1843    The localtime module allows the variables 'timezone', 'daylight',
1844    and 'altzone' to be in common storage shared with other modules,
1845    and declares them in case the system <time.h> does not.
1846    (Problems reported by Kees Dekker.)
1847
1848    On platforms with tm_zone, strftime.c now assumes it is not NULL.
1849    This simplifies the code and is consistent with zdump.c.
1850    (Problem reported by Christos Zoulas.)
1851
1852  Changes affecting documentation
1853
1854   The tzfile man page now documents that transition times denote the
1855   starts (not the ends) of the corresponding time periods.
1856   (Ambiguity reported by Bill Seymour.)
1857
1858
1859Release 2015f - 2015-08-10 18:06:56 -0700
1860
1861  Changes affecting future timestamps
1862
1863    North Korea switches to +0830 on 2015-08-15.  (Thanks to Steffen Thorsen.)
1864    The abbreviation remains "KST".  (Thanks to Robert Elz.)
1865
1866    Uruguay no longer observes DST.  (Thanks to Steffen Thorsen
1867    and Pablo Camargo.)
1868
1869  Changes affecting past and future timestamps
1870
1871    Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
1872    (Thanks to Roman Tudos.)
1873
1874  Changes affecting data format and code
1875
1876    zic's '-y YEARISTYPE' option is no longer documented.  The TYPE
1877    field of a Rule line should now be '-'; the old values 'even',
1878    'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented.
1879    Although the implementation has not changed, these features do not
1880    work in the default installation, they are not used in the data,
1881    and they are now considered obsolescent.
1882
1883    zic now checks that two rules don't take effect at the same time.
1884    (Thanks to Jon Skeet and Arthur David Olson.)  Constraints on
1885    simultaneity are now documented.
1886
1887    The two characters '%z' in a zone format now stand for the UT
1888    offset, e.g., '-07' for seven hours behind UT and '+0530' for
1889    five hours and thirty minutes ahead.  This better supports time
1890    zone abbreviations conforming to POSIX.1-2001 and later.
1891
1892  Changes affecting installed data files
1893
1894    Comments for America/Halifax and America/Glace_Bay have been improved.
1895    (Thanks to Brian Inglis.)
1896
1897    Data entries have been simplified for Atlantic/Canary, Europe/Simferopol,
1898    Europe/Sofia, and Europe/Tallinn.  This yields slightly smaller
1899    installed data files for Europe/Simferopol and Europe/Tallinn.
1900    It does not affect timestamps.  (Thanks to Howard Hinnant.)
1901
1902  Changes affecting code
1903
1904    zdump and zic no longer warn about valid time zone abbreviations
1905    like '-05'.
1906
1907    Some Visual Studio 2013 warnings have been suppressed.
1908    (Thanks to Kees Dekker.)
1909
1910    'date' no longer sets the time of day and its -a, -d, -n and -t
1911    options have been removed.  Long obsolescent, the implementation
1912    of these features had porting problems.  Builders no longer need
1913    to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H.
1914    (Thanks to Kees Dekker for pointing out the problem.)
1915
1916  Changes affecting documentation
1917
1918    The Theory file mentions naming issues earlier, as these seem to be
1919    poorly publicized (thanks to Gilmore Davidson for reporting the problem).
1920
1921    tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant).
1922
1923    Mention that Herbert Samuel introduced the term "Summer Time".
1924
1925
1926Release 2015e - 2015-06-13 10:56:02 -0700
1927
1928  Changes affecting future timestamps
1929
1930    Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00,
1931    not 06-13 and 07-18 as we had guessed.  (Thanks to Milamber.)
1932
1933    Assume Cayman Islands will observe DST starting next year, using US rules.
1934    Although it isn't guaranteed, it is the most likely.
1935
1936  Changes affecting data format
1937
1938    The file 'iso3166.tab' now uses UTF-8, so that its entries can better
1939    spell the names of Åland Islands, Côte d'Ivoire, and Réunion.
1940
1941  Changes affecting code
1942
1943    When displaying data, tzselect converts it to the current locale's
1944    encoding if the iconv command works.  (Problem reported by random832.)
1945
1946    tzselect no longer mishandles Dominica, fixing a bug introduced
1947    in Release 2014f.  (Problem reported by Owen Leibman.)
1948
1949    zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\".
1950    This fixes a bug introduced in Release 2014f.
1951    (Problem reported by Leonardo Chiquitto.)
1952
1953
1954Release 2015d - 2015-04-24 08:09:46 -0700
1955
1956  Changes affecting future timestamps
1957
1958    Egypt will not observe DST in 2015 and will consider canceling it
1959    permanently.  For now, assume no DST indefinitely.
1960    (Thanks to Ahmed Nazmy and Tim Parenti.)
1961
1962  Changes affecting past timestamps
1963
1964    America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not
1965    1966-07-01.  Also, Yukon's time zone history is documented better.
1966    (Thanks to Brian Inglis and Dennis Ferguson.)
1967
1968  Change affecting past and future time zone abbreviations
1969
1970    The abbreviations for Hawaii-Aleutian standard and daylight times
1971    have been changed from HAST/HADT to HST/HDT, as per US Government
1972    Printing Office style.  This affects only America/Adak since 1983,
1973    as America/Honolulu was already using the new style.
1974
1975  Changes affecting code
1976
1977   zic has some minor performance improvements.
1978
1979
1980Release 2015c - 2015-04-11 08:55:55 -0700
1981
1982  Changes affecting future timestamps
1983
1984    Egypt's spring-forward transition is at 24:00 on April's last Thursday,
1985    not 00:00 on April's last Friday.  2015's transition will therefore be on
1986    Thursday, April 30 at 24:00, not Friday, April 24 at 00:00.  Similar fixes
1987    apply to 2026, 2037, 2043, etc.  (Thanks to Steffen Thorsen.)
1988
1989  Changes affecting past timestamps
1990
1991    The following changes affect some pre-1991 Chile-related timestamps
1992    in America/Santiago, Antarctica/Palmer, and Pacific/Easter.
1993
1994      The 1910 transition was January 10, not January 1.
1995
1996      The 1918 transition was September 10, not September 1.
1997
1998      The UT -04 time observed from 1932 to 1942 is now considered to
1999      be standard time, not year-round DST.
2000
2001      Santiago observed DST (UT -03) from 1946-07-15 through
2002      1946-08-31, then reverted to standard time, then switched to -05
2003      on 1947-04-01.
2004
2005      Assume transitions before 1968 were at 00:00, since we have no data
2006      saying otherwise.
2007
2008      The spring 1988 transition was 1988-10-09, not 1988-10-02.
2009      The fall 1990 transition was 1990-03-11, not 1990-03-18.
2010
2011      Assume no UT offset change for Pacific/Easter on 1890-01-01,
2012      and omit all transitions on Pacific/Easter from 1942 through 1946
2013      since we have no data suggesting that they existed.
2014
2015    One more zone has been turned into a link, as it differed
2016    from an existing zone only for older timestamps.  As usual,
2017    this change affects UT offsets in pre-1970 timestamps only.
2018    The zone's old contents have been moved to the 'backzone' file.
2019    The affected zone is America/Montreal.
2020
2021  Changes affecting commentary
2022
2023    Mention the TZUpdater tool.
2024
2025    Mention "The Time Now".  (Thanks to Brandon Ramsey.)
2026
2027
2028Release 2015b - 2015-03-19 23:28:11 -0700
2029
2030  Changes affecting future timestamps
2031
2032    Mongolia will start observing DST again this year, from the last
2033    Saturday in March at 02:00 to the last Saturday in September at 00:00.
2034    (Thanks to Ganbold Tsagaankhuu.)
2035
2036    Palestine will start DST on March 28, not March 27.  Also,
2037    correct the fall 2014 transition from September 26 to October 24.
2038    Adjust future predictions accordingly.  (Thanks to Steffen Thorsen.)
2039
2040  Changes affecting past timestamps
2041
2042    The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a
2043    regression.  (Thanks to Stuart Bishop for reporting the problem.)
2044
2045    Some more zones have been turned into links, when they differed
2046    from existing zones only for older timestamps.  As usual,
2047    these changes affect UT offsets in pre-1970 timestamps only.
2048    Their old contents have been moved to the 'backzone' file.
2049    The affected zones are: America/Antigua, America/Cayman,
2050    Pacific/Midway, and Pacific/Saipan.
2051
2052  Changes affecting time zone abbreviations
2053
2054    Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD".
2055    (Thanks to Hank W.)
2056
2057  Changes affecting code
2058
2059    Fix integer overflow bug in reference 'mktime' implementation.
2060    (Problem reported by Jörg Richter.)
2061
2062    Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries
2063    to be used in the same executable as standard-library time_t functions.
2064    (Problems reported by Bradley White.)
2065
2066  Changes affecting commentary
2067
2068    Cite the recent Mexican decree changing Quintana Roo's time zone.
2069    (Thanks to Carlos Raúl Perasso.)
2070
2071    Likewise for the recent Chilean decree.  (Thanks to Eduardo Romero Urra.)
2072
2073    Update info about Mars time.
2074
2075
2076Release 2015a - 2015-01-29 22:35:20 -0800
2077
2078  Changes affecting future timestamps
2079
2080    The Mexican state of Quintana Roo, represented by America/Cancun,
2081    will shift from Central Time with DST to Eastern Time without DST
2082    on 2015-02-01 at 02:00.  (Thanks to Steffen Thorsen and Gwillim Law.)
2083
2084    Chile will not change clocks in April or thereafter; its new standard time
2085    will be its old daylight saving time.  This affects America/Santiago,
2086    Pacific/Easter, and Antarctica/Palmer.  (Thanks to Juan Correa.)
2087
2088    New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.
2089    (Thanks to Tim Parenti.)
2090
2091  Changes affecting past timestamps
2092
2093    Iceland observed DST in 1919 and 1921, and its 1939 fallback
2094    transition was Oct. 29, not Nov. 29.  Remove incorrect data from
2095    Shanks about time in Iceland between 1837 and 1908.
2096
2097    Some more zones have been turned into links, when they differed
2098    from existing zones only for older timestamps.  As usual,
2099    these changes affect UT offsets in pre-1970 timestamps only.
2100    Their old contents have been moved to the 'backzone' file.
2101    The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait,
2102    and Asia/Muscat.
2103
2104  Changes affecting code
2105
2106    tzalloc now scrubs time zone abbreviations compatibly with the way
2107    that tzset always has, by replacing invalid bytes with '_' and by
2108    shortening too-long abbreviations.
2109
2110    tzselect ports to POSIX awk implementations, no longer mishandles
2111    POSIX TZ settings when GNU awk is used, and reports POSIX TZ
2112    settings to the user.  (Thanks to Stefan Kuhn.)
2113
2114  Changes affecting build procedure
2115
2116    'make check' now checks for links to links in the data.
2117    One such link (for Africa/Asmera) has been fixed.
2118    (Thanks to Stephen Colebourne for pointing out the problem.)
2119
2120  Changes affecting commentary
2121
2122    The leapseconds file commentary now mentions the expiration date.
2123    (Problem reported by Martin Burnicki.)
2124
2125    Update Mexican Library of Congress URL.
2126
2127
2128Release 2014j - 2014-11-10 17:37:11 -0800
2129
2130  Changes affecting current and future timestamps
2131
2132    Turks & Caicos' switch from US eastern time to UT -04 year-round
2133    did not occur on 2014-11-02 at 02:00.  It's currently scheduled
2134    for 2015-11-01 at 02:00.  (Thanks to Chris Walton.)
2135
2136  Changes affecting past timestamps
2137
2138    Many pre-1989 timestamps have been corrected for Asia/Seoul and
2139    Asia/Pyongyang, based on sources for the Korean-language Wikipedia
2140    entry for time in Korea.  (Thanks to Sanghyuk Jung.)  Also, no
2141    longer guess that Pyongyang mimicked Seoul time after World War II,
2142    as this is politically implausible.
2143
2144    Some more zones have been turned into links, when they differed
2145    from existing zones only for older timestamps.  As usual,
2146    these changes affect UT offsets in pre-1970 timestamps only.
2147    Their old contents have been moved to the 'backzone' file.
2148    The affected zones are: Africa/Addis_Ababa, Africa/Asmara,
2149    Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala,
2150    Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and
2151    Indian/Mayotte.
2152
2153  Changes affecting commentary
2154
2155    The commentary is less enthusiastic about Shanks as a source,
2156    and is more careful to distinguish UT from UTC.
2157
2158
2159Release 2014i - 2014-10-21 22:04:57 -0700
2160
2161  Changes affecting future timestamps
2162
2163    Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00.
2164    (Thanks to Ken Rylander for the heads-up.)  Guess that future
2165    years will use a similar pattern.
2166
2167    A new Zone Pacific/Bougainville, for the part of Papua New Guinea
2168    that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00.
2169    (Thanks to Kiley Walbom for the heads-up.)
2170
2171  Changes affecting time zone abbreviations
2172
2173    Since Belarus is not changing its clocks even though Moscow is,
2174    the time zone abbreviation in Europe/Minsk is changing from FET
2175    to its more-traditional value MSK on 2014-10-26 at 01:00.
2176    (Thanks to Alexander Bokovoy for the heads-up about Belarus.)
2177
2178    The new abbreviation IDT stands for the pre-1976 use of UT +08 in
2179    Indochina, to distinguish it better from ICT (+07).
2180
2181  Changes affecting past timestamps
2182
2183    Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976
2184    (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's
2185    authoritative book).  Asia/Ho_Chi_Minh has been added to
2186    zone1970.tab, to give tzselect users in Vietnam two choices,
2187    since north and south Vietnam disagreed after our 1970 cutoff.
2188
2189    Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as
2190    they differed from existing zones only for older timestamps.  As
2191    usual, these changes affect pre-1970 timestamps only.  Their old
2192    contents have been moved to the 'backzone' file.
2193
2194  Changes affecting code
2195
2196    The time-related library functions now set errno on failure, and
2197    some crashes in the new tzalloc-related library functions have
2198    been fixed.  (Thanks to Christos Zoulas for reporting most of
2199    these problems and for suggesting fixes.)
2200
2201    If USG_COMPAT is defined and the requested timestamp is standard time,
2202    the tz library's localtime and mktime functions now set the extern
2203    variable timezone to a value appropriate for that timestamp; and
2204    similarly for ALTZONE, daylight saving time, and the altzone variable.
2205    This change is a companion to the tzname change in 2014h, and is
2206    designed to make timezone and altzone more compatible with tzname.
2207
2208    The tz library's functions now set errno to EOVERFLOW if they fail
2209    because the result cannot be represented.  ctime and ctime_r now
2210    return NULL and set errno when a timestamp is out of range, rather
2211    than having undefined behavior.
2212
2213    Some bugs associated with the new 2014g functions have been fixed.
2214    This includes a bug that largely incapacitated the new functions
2215    time2posix_z and posix2time_z.  (Thanks to Christos Zoulas.)
2216    It also includes some uses of uninitialized variables after tzalloc.
2217    The new code uses the standard type 'ssize_t', which the Makefile
2218    now gives porting advice about.
2219
2220  Changes affecting commentary
2221
2222    Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis).
2223
2224
2225Release 2014h - 2014-09-25 18:59:03 -0700
2226
2227  Changes affecting past timestamps
2228
2229    America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28.
2230
2231    Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01,
2232    not 1920-01-06.  The old entry was based on a misinterpretation of Shanks.
2233
2234    Some more zones have been turned into links, when they differed
2235    from existing zones only for older timestamps.  As usual,
2236    these changes affect UT offsets in pre-1970 timestamps only.
2237    Their old contents have been moved to the 'backzone' file.
2238    The affected zones are: Africa/Blantyre, Africa/Bujumbura,
2239    Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi,
2240    Africa/Lusaka, Africa/Maseru, and Africa/Mbabane.
2241
2242  Changes affecting code
2243
2244    zdump -V and -v now output gmtoff= values on all platforms,
2245    not merely on platforms defining TM_GMTOFF.
2246
2247    The tz library's localtime and mktime functions now set tzname to a value
2248    appropriate for the requested timestamp, and zdump now uses this
2249    on platforms not defining TM_ZONE, fixing a 2014g regression.
2250    (Thanks to Tim Parenti for reporting the problem.)
2251
2252    The tz library no longer sets tzname if localtime or mktime fails.
2253
2254    zdump -c no longer mishandles transitions near year boundaries.
2255    (Thanks to Tim Parenti for reporting the problem.)
2256
2257    An access to uninitialized data has been fixed.
2258    (Thanks to Jörg Richter for reporting the problem.)
2259
2260    When THREAD_SAFE is defined, the code ports to the C11 memory model.
2261    A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined
2262    and two threads race to initialize data used by gmtime-like functions.
2263    (Thanks to Andy Heninger for reporting the problems.)
2264
2265  Changes affecting build procedure
2266
2267    'make check' now checks better for properly-sorted data.
2268
2269  Changes affecting documentation and commentary
2270
2271    zdump's gmtoff=N output is now documented, and its isdst=D output
2272    is now documented to possibly output D values other than 0 or 1.
2273
2274    zdump -c's treatment of years is now documented to use the
2275    Gregorian calendar and Universal Time without leap seconds,
2276    and its behavior at cutoff boundaries is now documented better.
2277    (Thanks to Arthur David Olson and Tim Parenti for reporting the problems.)
2278
2279    Programs are now documented to use the proleptic Gregorian calendar.
2280    (Thanks to Alan Barrett for the suggestion.)
2281
2282    Fractional-second GMT offsets have been documented for civil time
2283    in 19th-century Chennai, Jakarta, and New York.
2284
2285
2286Release 2014g - 2014-08-28 12:31:23 -0700
2287
2288  Changes affecting future timestamps
2289
2290    Turks & Caicos is switching from US eastern time to UT -04
2291    year-round, modeled as a switch on 2014-11-02 at 02:00.
2292    [As noted in 2014j, this switch was later delayed.]
2293
2294  Changes affecting past timestamps
2295
2296    Time in Russia or the USSR before 1926 or so has been corrected by
2297    a few seconds in the following zones: Asia/Irkutsk,
2298    Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi,
2299    Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara.  For
2300    Asia/Yekaterinburg the correction is a few minutes.  (Thanks to
2301    Vladimir Karpinsky.)
2302
2303    The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
2304    This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
2305    Atlantic/Azores, and Atlantic/Madeira.  Also, Lisbon's pre-1912
2306    GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32.
2307    (Thanks to Stephen Colebourne for pointing to the decree.)
2308
2309    Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59.
2310
2311    A new file 'backzone' contains data which may appeal to
2312    connoisseurs of old timestamps, although it is out of scope for
2313    the tz database, is often poorly sourced, and contains some data
2314    that is known to be incorrect.  The new file is not recommended
2315    for ordinary use and its entries are not installed by default.
2316    (Thanks to Lester Caine for the high-quality Jersey, Guernsey, and
2317    Isle of Man entries.)
2318
2319    Some more zones have been turned into links, when they differed
2320    from existing zones only for older timestamps.  As usual,
2321    these changes affect UT offsets in pre-1970 timestamps only.
2322    Their old contents have been moved to the 'backzone' file.
2323    The affected zones are: Africa/Bangui, Africa/Brazzaville,
2324    Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda,
2325    Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo.
2326
2327  Changes affecting code
2328
2329    Unless NETBSD_INSPIRED is defined to 0, the tz library now
2330    supplies functions for creating and using objects that represent
2331    timezones. The new functions are tzalloc, tzfree, localtime_rz,
2332    mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and
2333    time2posix_z.  They are intended for performance: for example,
2334    localtime_rz (unlike localtime_r) is trivially thread-safe without
2335    locking.  (Thanks to Christos Zoulas for proposing NetBSD-inspired
2336    functions, and to Alan Barrett and Jonathan Lennox for helping to
2337    debug the change.)
2338
2339    zdump now builds with the tz library unless USE_LTZ is defined to 0,
2340    This lets zdump use tz features even if the system library lacks them.
2341    To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
2342    TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.
2343
2344    zdump now uses localtime_rz if available, as it's significantly faster,
2345    and it can help zdump better diagnose invalid timezone names.
2346    Define HAVE_LOCALTIME_RZ to 0 to suppress this.  HAVE_LOCALTIME_RZ
2347    defaults to 1 if NETBSD_INSPIRED && USE_LTZ.  When localtime_rz is
2348    not available, zdump now uses localtime_r and tzset if available,
2349    as this is a bit cleaner and faster than plain localtime.  Compile
2350    with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
2351    lacks these two functions.
2352
2353    If THREAD_SAFE is defined to 1, the tz library is now thread-safe.
2354    Although not needed for tz's own applications, which are single-threaded,
2355    this supports POSIX better if the tz library is used in multithreaded apps.
2356
2357    Some crashes have been fixed when zdump or the tz library is given
2358    invalid or outlandish input.
2359
2360    The tz library no longer mishandles leap seconds on platforms with
2361    unsigned time_t in timezones that lack ordinary transitions after 1970.
2362
2363    The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not
2364    already defined, to make it easier to configure on common platforms.
2365    Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this.
2366
2367    Unless the new macro UNINIT_TRAP is defined to 1, the tz code now
2368    assumes that reading uninitialized memory yields garbage values
2369    but does not cause other problems such as traps.
2370
2371    If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
2372    more likely to guess right for ambiguous timestamps near
2373    transitions where tm_isdst does not change.
2374
2375    If HAVE_STRFTIME_L is defined to 1, the tz library now defines
2376    strftime_l for compatibility with recent versions of POSIX.
2377    Only the C locale is supported, though.  HAVE_STRFTIME_L defaults
2378    to 1 on recent POSIX versions, and to 0 otherwise.
2379
2380    tzselect -c now uses a hybrid distance measure that works better
2381    in Africa.  (Thanks to Alan Barrett for noting the problem.)
2382
2383    The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used,
2384    or when time_tz is defined.
2385
2386    When HAVE_UTMPX_H is set the 'date' command now builds on systems
2387    whose <utmpx.h> file does not define WTMPX_FILE, and when setting
2388    the date it updates the wtmpx file if _PATH_WTMPX is defined.
2389    This affects GNU/Linux and similar systems.
2390
2391    For easier maintenance later, some C code has been simplified,
2392    some lint has been removed, and the code has been tweaked so that
2393    plain 'make' is more likely to work.
2394
2395    The C type 'bool' is now used for boolean values, instead of 'int'.
2396
2397    The long-obsolete LOCALE_HOME code has been removed.
2398
2399    The long-obsolete 'gtime' function has been removed.
2400
2401  Changes affecting build procedure
2402
2403    'zdump' no longer links in ialloc.o, as it's not needed.
2404
2405    'make check_time_t_alternatives' no longer assumes GNU diff.
2406
2407  Changes affecting distribution tarballs
2408
2409    The files checktab.awk and zoneinfo2tdf.pl are now distributed in
2410    the tzdata tarball instead of the tzcode tarball, since they help
2411    maintain the data.  The NEWS and Theory files are now also
2412    distributed in the tzdata tarball, as they're relevant for data.
2413    (Thanks to Alan Barrett for pointing this out.)  Also, the
2414    leapseconds.awk file is no longer distributed in the tzcode
2415    tarball, since it belongs in the tzdata tarball (where 2014f
2416    inadvertently also distributed it).
2417
2418  Changes affecting documentation and commentary
2419
2420    A new file CONTRIBUTING is distributed.  (Thanks to Tim Parenti for
2421    suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms
2422    for debugging it.)
2423
2424    The man pages have been updated to use function prototypes,
2425    to document thread-safe variants like localtime_r, and to document
2426    the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and
2427    mktime_z.
2428
2429    The fields in Link lines have been renamed to be more descriptive
2430    and more like the parameters of 'ln'.  LINK-FROM has become TARGET,
2431    and LINK-TO has become LINK-NAME.
2432
2433    tz-link.htm mentions the IETF's tzdist working group; Windows
2434    Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab.
2435
2436    Some broken URLs have been fixed in the commentary.  (Thanks to
2437    Lester Caine.)
2438
2439    Commentary about Philippines DST has been updated, and commentary
2440    on pre-1970 time in India has been added.
2441
2442
2443Release 2014f - 2014-08-05 17:42:36 -0700
2444
2445  Changes affecting future timestamps
2446
2447    Russia will subtract an hour from most of its time zones on 2014-10-26
2448    at 02:00 local time.  (Thanks to Alexander Krivenyshev.)
2449    There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky
2450    Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug
2451    (Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast
2452    (Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic
2453    (Europe/Samara) are not changing their clocks.  The changed zones are
2454    Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd,
2455    Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk,
2456    Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga,
2457    Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours
2458    subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected,
2459    but not its UTC offset.  Two zones are added: Asia/Chita (split
2460    from Asia/Yakutsk, and also with two hours subtracted) and
2461    Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour
2462    subtracted).  (Thanks to Tim Parenti for much of the above.)
2463
2464  Changes affecting time zone abbreviations
2465
2466    Australian eastern time zone abbreviations are now AEST/AEDT not EST,
2467    and similarly for the other Australian zones.  That is, for eastern
2468    standard and daylight saving time the abbreviations are AEST and AEDT
2469    instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT,
2470    and AWST/AWDT are now used instead of the former CST, CWST, and WST.
2471    This change does not affect UT offsets, only time zone abbreviations.
2472    (Thanks to Rich Tibbett and many others.)
2473
2474    Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07)
2475    effective 2014-10-26 at 02:00 local time.
2476
2477    The time zone abbreviation for Xinjiang Time (observed in Ürümqi)
2478    has been changed from URUT to XJT.  (Thanks to Luther Ma.)
2479
2480    Prefer MSK/MSD for Moscow time in Russia, even in other cities.
2481    Similarly, prefer EET/EEST for eastern European time in Russia.
2482
2483    Change time zone abbreviations in (western) Samoa to use "ST" and
2484    "DT" suffixes, as this is more likely to match common practice.
2485    Prefix "W" to (western) Samoa time when its standard-time offset
2486    disagrees with that of American Samoa.
2487
2488    America/Metlakatla now uses PST, not MeST, to abbreviate its time zone.
2489
2490    Time zone abbreviations have been updated for Japan's two time
2491    zones used 1896-1937.  JWST now stands for Western Standard
2492    Time, and JCST for Central Standard Time (formerly this was CJT).
2493    These abbreviations are now used for time in Korea, Taiwan,
2494    and Sakhalin while controlled by Japan.
2495
2496  Changes affecting past timestamps
2497
2498    China's five zones have been simplified to two, since the post-1970
2499    differences in the other three seem to have been imaginary.  The
2500    zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been
2501    removed; backwards-compatibility links still work, albeit with
2502    different behaviors for timestamps before May 1980.  Asia/Urumqi's
2503    1980 transition to UT +08 has been removed, so that it is now at
2504    +06 and not +08.  (Thanks to Luther Ma and to Alois Treindl;
2505    Treindl sent helpful translations of two papers by Guo Qingsheng.)
2506
2507    Some zones have been turned into links, when they differed from existing
2508    zones only for older UT offsets where data entries were likely invented.
2509    These changes affect UT offsets in pre-1970 timestamps only.  This is
2510    similar to the change in release 2013e, except this time for western
2511    Africa.  The affected zones are: Africa/Bamako, Africa/Banjul,
2512    Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome,
2513    Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and
2514    Atlantic/St_Helena.  This also affects the backwards-compatibility
2515    link Africa/Timbuktu.  (Thanks to Alan Barrett, Stephen Colebourne,
2516    Tim Parenti, and David Patte for reporting problems in earlier
2517    versions of this change.)
2518
2519    Asia/Shanghai's pre-standard-time UT offset has been changed from
2520    8:05:57 to 8:05:43, the location of Xujiahui Observatory.  Its
2521    transition to standard time has been changed from 1928 to 1901.
2522
2523    Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01,
2524    then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945.
2525    In 1946 it observed DST from 05-15 through 09-30; in 1947
2526    from 04-15 through 10-31; and in 1979 from 07-01 through 09-30.
2527    (Thanks to Yu-Cheng Chuang.)
2528
2529    Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950.
2530
2531    Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not
2532    10-03 at 00:00.  (Thanks to Konstantin Hyppönen.)
2533
2534    Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the
2535    period from 1911 to 1950.
2536
2537    Pacific/Chatham has been changed to New Zealand standard time plus
2538    45 minutes for the period before 1957, reflecting a 1956 remark in
2539    the New Zealand parliament.
2540
2541    Europe/Budapest has several pre-1946 corrections: in 1918 the transition
2542    out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in
2543    1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08
2544    not 04-06 at 02:00; and there was no DST in 1920.
2545
2546    Africa/Accra is now assumed to have observed DST from 1920 through 1935.
2547
2548    Time in Russia before 1927 or so has been corrected by a few seconds in
2549    the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi,
2550    Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and
2551    Europe/Riga.  Also, Moscow's location has been changed to its Kilometer 0
2552    point.  (Thanks to Vladimir Karpinsky for the Moscow changes.)
2553
2554  Changes affecting data format
2555
2556    A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data.
2557    The new file's extended format allows multiple country codes per zone.
2558    The older file is still installed but is deprecated; its format is
2559    not changing and it will still be distributed for a while, but new
2560    applications should use the new file.
2561
2562    The new file format simplifies maintenance of obscure locations.
2563    To test this, it adds coverage for the Crozet Islands and the
2564    Scattered Islands.  (Thanks to Tobias Conradi and Antoine Leca.)
2565
2566    The file 'iso3166.tab' is planned to switch from ASCII to UTF-8.
2567    It is still ASCII now, but commentary about the switch has been added.
2568    The new file 'zone1970.tab' already uses UTF-8.
2569
2570  Changes affecting code
2571
2572    'localtime', 'mktime', etc. now use much less stack space if ALL_STATE
2573    is defined.  (Thanks to Elliott Hughes for reporting the problem.)
2574
2575    'zic' no longer mishandles input when ignoring case in locales that
2576    are not compatible with English, e.g., unibyte Turkish locales when
2577    compiled with HAVE_GETTEXT.
2578
2579    Error diagnostics of 'zic' and 'yearistype' have been reworded so that
2580    they no longer use ASCII '-' as if it were a dash.
2581
2582    'zic' now rejects output file names that contain '.' or '..' components.
2583    (Thanks to Tim Parenti for reporting the problem.)
2584
2585    'zic -v' now warns about output file names that do not follow
2586    POSIX rules, or that contain a digit or '.'.  (Thanks to Arthur
2587    David Olson for starting the ball rolling on this.)
2588
2589    Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0.
2590
2591  Changes affecting build procedure
2592
2593    'zic' no longer links in localtime.o and asctime.o, as they're not needed.
2594    (Thanks to John Cochran.)
2595
2596  Changes affecting documentation and commentary
2597
2598    The 'Theory' file documents legacy names, the longstanding
2599    exceptions to the POSIX-inspired file name rules.
2600
2601    The 'zic' documentation clarifies the role of time types when
2602    interpreting dates.  (Thanks to Arthur David Olson.)
2603
2604    Documentation and commentary now prefer UTF-8 to US-ASCII,
2605    allowing the use of proper accents in foreign words and names.
2606    Code and data have not changed because of this.  (Thanks to
2607    Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug
2608    this.)
2609
2610    Non-HTML documentation and commentary now use plain-text URLs instead of
2611    HTML insertions, and are more consistent about bracketing URLs when they
2612    are not already surrounded by white space.  (Thanks to suggestions by
2613    Steffen Nurpmeso.)
2614
2615    There is new commentary about Xujiahui Observatory, the five time-zone
2616    project in China from 1918 to 1949, timekeeping in Japanese-occupied
2617    Shanghai, and Tibet Time in the 1950s.  The sharp-eyed can spot the
2618    warlord Jin Shuren in the data.
2619
2620    Commentary about the coverage of each Russian zone has been standardized.
2621    (Thanks to Tim Parenti.)
2622
2623    There is new commentary about contemporary timekeeping in Ethiopia.
2624
2625    Obsolete comments about a 2007 proposal for DST in Kuwait has been removed.
2626
2627    There is new commentary about time in Poland in 1919.
2628
2629    Proper credit has been given to DST inventor George Vernon Hudson.
2630
2631    Commentary about time in Metlakatla, AK and Resolute, NU has been
2632    improved, with a new source for the former.
2633
2634    In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it
2635    is uninhabited.
2636
2637    Commentary about permanent Antarctic bases has been updated.
2638
2639    Several typos have been corrected.  (Thanks to Tim Parenti for
2640    contributing some of these fixes.)
2641
2642    tz-link.htm now mentions the JavaScript libraries Moment Timezone,
2643    TimezoneJS.Date, Walltime-js, and Timezone.  (Thanks to a heads-up
2644    from Matt Johnson.)  Also, it mentions the Go 'latlong' package.
2645    (Thanks to a heads-up from Dirkjan Ochtman.)
2646
2647    The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998
2648    have been removed.  These obsolescent US Naval Observatory entries were no
2649    longer helpful for maintenance.  (Thanks to Tim Parenti for the suggestion.)
2650
2651
2652Release 2014e - 2014-06-12 21:53:52 -0700
2653
2654  Changes affecting near-future timestamps
2655
2656    Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00.
2657    (Thanks to Imed Chihi.)  Guess that from 2015 on Egypt will temporarily
2658    switch to standard time at 24:00 the last Thursday before Ramadan, and
2659    back to DST at 00:00 the first Friday after Ramadan.
2660
2661    Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00.  (Thanks
2662    to Milamber Space Network.)  Guess that from 2015 on Morocco will
2663    temporarily switch to standard time at 03:00 the last Saturday before
2664    Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.
2665
2666  Changes affecting past timestamps
2667
2668    The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of
2669    "MSD" for Moscow's double daylight time in summer 1921.  Also, a typo
2670    "VLASST" has been repaired to be "VLAST" for Vladivostok summer time
2671    in 1991.  (Thanks to Hank W. for reporting the problems.)
2672
2673  Changes affecting commentary
2674
2675    tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the
2676    draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and
2677    removes stale pointers to World Time Explorer and WORLDTIME.
2678
2679
2680Release 2014d - 2014-05-27 21:34:40 -0700
2681
2682  Changes affecting code
2683
2684    zic no longer generates files containing timestamps before the Big Bang.
2685    This works around GNOME glib bug 878
2686    <https://gitlab.gnome.org/GNOME/glib/issues/878>
2687    (Thanks to Leonardo Chiquitto for reporting the bug, and to
2688    Arthur David Olson and James Cloos for suggesting improvements to the fix.)
2689
2690  Changes affecting documentation
2691
2692    tz-link.htm now mentions GNOME.
2693
2694
2695Release 2014c - 2014-05-13 07:44:13 -0700
2696
2697  Changes affecting near-future timestamps
2698
2699    Egypt observes DST starting 2014-05-15 at 24:00.
2700    (Thanks to Ahmad El-Dardiry and Gunther Vermier.)
2701    Details have not been announced, except that DST will not be observed
2702    during Ramadan.  Guess that DST will stop during the same Ramadan dates as
2703    Morocco, and that Egypt's future spring and fall transitions will be the
2704    same as 2010 when it last observed DST, namely April's last Friday at
2705    00:00 to September's last Thursday at 23:00 standard time.  Also, guess
2706    that Ramadan transitions will be at 00:00 standard time.
2707
2708  Changes affecting code
2709
2710    zic now generates transitions for minimum time values, eliminating guesswork
2711    when handling low-valued timestamps.  (Thanks to Arthur David Olson.)
2712
2713    Port to Cygwin sans glibc.  (Thanks to Arthur David Olson.)
2714
2715  Changes affecting commentary and documentation
2716
2717    Remove now-confusing comment about Jordan.  (Thanks to Oleksii Nochovnyi.)
2718
2719
2720Release 2014b - 2014-03-24 21:28:50 -0700
2721
2722  Changes affecting near-future timestamps
2723
2724    Crimea switches to Moscow time on 2014-03-30 at 02:00 local time.
2725    (Thanks to Alexander Krivenyshev.)  Move its zone.tab entry from UA to RU.
2726
2727    New entry for Troll station, Antarctica.  (Thanks to Paul-Inge Flakstad and
2728    Bengt-Inge Larsson.)  This is currently an approximation; a better version
2729    will require the zic and localtime fixes mentioned below, and the plan is
2730    to wait for a while until at least the zic fixes propagate.
2731
2732  Changes affecting code
2733
2734    'zic' and 'localtime' no longer reject locations needing four transitions
2735    per year for the foreseeable future.  (Thanks to Andrew Main (Zefram).)
2736    Also, 'zic' avoids some unlikely failures due to integer overflow.
2737
2738  Changes affecting build procedure
2739
2740    'make check' now detects Rule lines defined but never used.
2741    The NZAQ rules, an instance of this problem, have been removed.
2742
2743  Changes affecting commentary and documentation
2744
2745    Fix Tuesday/Thursday typo in description of time in Israel.
2746    (Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.)
2747
2748    Microsoft Windows 8.1 doesn't support tz database names.  (Thanks
2749    to Donald MacQueen.)  Instead, the Microsoft Windows Store app
2750    library supports them.
2751
2752    Add comments about Johnston Island time in the 1960s.
2753    (Thanks to Lyle McElhaney.)
2754
2755    Morocco's 2014 DST start will be as predicted.
2756    (Thanks to Sebastien Willemijns.)
2757
2758
2759Release 2014a - 2014-03-07 23:30:29 -0800
2760
2761  Changes affecting near-future timestamps
2762
2763    Turkey begins DST on 2014-03-31, not 03-30.  (Thanks to Faruk Pasin for
2764    the heads-up, and to Tim Parenti for simplifying the update.)
2765
2766  Changes affecting past timestamps
2767
2768    Fiji ended DST on 2014-01-19 at 02:00, not the previously-scheduled 03:00.
2769    (Thanks to Steffen Thorsen.)
2770
2771    Ukraine switched from Moscow to Eastern European time on 1990-07-01
2772    (not 1992-01-01), and observed DST during the entire next winter.
2773    (Thanks to Vladimir in Moscow via Alois Treindl.)
2774
2775    In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03.
2776    (Thanks to Avigdor Finkelstein.)
2777
2778  Changes affecting code
2779
2780    A uninitialized-storage bug in 'localtime' has been fixed.
2781    (Thanks to Logan Chien.)
2782
2783  Changes affecting the build procedure
2784
2785    The settings for 'make check_web' now default to Ubuntu 13.10.
2786
2787  Changes affecting commentary and documentation
2788
2789    The boundary of the US Pacific time zone is given more accurately.
2790    (Thanks to Alan Mintz.)
2791
2792    Chile's 2014 DST will be as predicted.  (Thanks to José Miguel Garrido.)
2793
2794    Paraguay's 2014 DST will be as predicted.  (Thanks to Carlos Raúl Perasso.)
2795
2796    Better descriptions of countries with same time zone history as
2797    Trinidad and Tobago since 1970.  (Thanks to Alan Barrett for suggestion.)
2798
2799    Several changes affect tz-link.htm, the main web page.
2800
2801      Mention Time.is (thanks to Even Scharning) and WX-now (thanks to
2802      David Braverman).
2803
2804      Mention xCal (Internet RFC 6321) and jCal.
2805
2806      Microsoft has some support for tz database names.
2807
2808      CLDR data formats include both XML and JSON.
2809
2810      Mention Maggiolo's map of solar vs standard time.
2811      (Thanks to Arthur David Olson.)
2812
2813      Mention TZ4Net.  (Thanks to Matt Johnson.)
2814
2815      Mention the timezone-olson Haskell package.
2816
2817      Mention zeitverschiebung.net.  (Thanks to Martin Jäger.)
2818
2819      Remove moribund links to daylight-savings-time.info and to
2820      Simple Timer + Clocks.
2821
2822      Update two links.  (Thanks to Oscar van Vlijmen.)
2823
2824      Fix some formatting glitches, e.g., remove random newlines from
2825      abbr elements' title attributes.
2826
2827
2828Release 2013i - 2013-12-17 07:25:23 -0800
2829
2830  Changes affecting near-future timestamps:
2831
2832    Jordan switches back to standard time at 00:00 on December 20, 2013.
2833    The 2006-2011 transition schedule is planned to resume in 2014.
2834    (Thanks to Steffen Thorsen.)
2835
2836  Changes affecting past timestamps:
2837
2838    In 2004, Cuba began DST on March 28, not April 4.
2839    (Thanks to Steffen Thorsen.)
2840
2841  Changes affecting code
2842
2843    The compile-time flag NOSOLAR has been removed, as nowadays the
2844    benefit of slightly shrinking runtime table size is outweighed by the
2845    cost of disallowing potential future updates that exceed old limits.
2846
2847  Changes affecting documentation and commentary
2848
2849    The files solar87, solar88, and solar89 are no longer distributed.
2850    They were a negative experiment - that is, a demonstration that
2851    tz data can represent solar time only with some difficulty and error.
2852    Their presence in the distribution caused confusion, as Riyadh
2853    civil time was generally not solar time in those years.
2854
2855    tz-link.htm now mentions Noda Time.  (Thanks to Matt Johnson.)
2856
2857
2858Release 2013h - 2013-10-25 15:32:32 -0700
2859
2860  Changes affecting current and future timestamps:
2861
2862    Libya has switched its UT offset back to +02 without DST, instead
2863    of +01 with DST.  (Thanks to Even Scharning.)
2864
2865    Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules.
2866    (Thanks to Gwillim Law.)
2867
2868  Changes affecting future timestamps:
2869
2870    Acre and (we guess) western Amazonas will switch from UT -04 to -05
2871    on 2013-11-10.  This affects America/Rio_Branco and America/Eirunepe.
2872    (Thanks to Steffen Thorsen.)
2873
2874    Add entries for DST transitions in Morocco in the year 2038.
2875    This avoids some year-2038 glitches introduced in 2013g.
2876    (Thanks to Yoshito Umaoka for reporting the problem.)
2877
2878  Changes affecting API
2879
2880    The 'tzselect' command no longer requires the 'select' command,
2881    and should now work with /bin/sh on more platforms.  It also works
2882    around a bug in BusyBox awk before version 1.21.0.  (Thanks to
2883    Patrick 'P. J.' McDermott and Alan Barrett.)
2884
2885  Changes affecting code
2886
2887    Fix localtime overflow bugs with 32-bit unsigned time_t.
2888
2889    zdump no longer assumes sscanf returns maximal values on overflow.
2890
2891  Changes affecting the build procedure
2892
2893    The builder can specify which programs to use, if any, instead of
2894    'ar' and 'ranlib', and libtz.a is now built locally before being
2895    installed.  (Thanks to Michael Forney.)
2896
2897    A dependency typo in the 'zdump' rule has been fixed.
2898    (Thanks to Andrew Paprocki.)
2899
2900    The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f'
2901    work as specified by POSIX.2-1992 or later; this is portable nowadays.
2902
2903    'make clean' no longer removes 'leapseconds', since it's
2904    host-independent and is part of the distribution.
2905
2906    The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed.
2907
2908  Changes affecting documentation and commentary
2909
2910    tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol
2911    (thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle).
2912
2913    Update URLs in tz-link page.  Add URLs for Microsoft Windows, since
2914    8.1 introduces tz support.  Remove URLs for Tru64 and UnixWare (no
2915    longer maintained) and for old advisories.  SOFA now does C.
2916
2917Release 2013g - 2013-09-30 21:08:26 -0700
2918
2919  Changes affecting current and near-future timestamps
2920
2921    Morocco now observes DST from the last Sunday in March to the last
2922    Sunday in October, not April to September respectively.  (Thanks
2923    to Steffen Thorsen.)
2924
2925  Changes affecting 'zic'
2926
2927    'zic' now runs on platforms that lack both hard links and symlinks.
2928    (Thanks to Theo Veenker for reporting the problem, for MinGW.)
2929    Also, fix some bugs on platforms that lack hard links but have symlinks.
2930
2931    'zic -v' again warns that Asia/Tehran has no POSIX environment variable
2932    to predict the far future, fixing a bug introduced in 2013e.
2933
2934  Changes affecting the build procedure
2935
2936    The 'leapseconds' file is again put into the tzdata tarball.
2937    Also, 'leapseconds.awk', so tzdata is self-contained.  (Thanks to
2938    Matt Burgess and Ian Abbott.)  The timestamps of these and other
2939    dependent files in tarballs are adjusted more consistently.
2940
2941  Changes affecting documentation and commentary
2942
2943    The README file is now part of the data tarball as well as the code.
2944    It now states that files are public domain unless otherwise specified.
2945    (Thanks to Andrew Main (Zefram) for asking for clarifications.)
2946    Its details about the 1989 release moved to a place of honor near
2947    the end of NEWS.
2948
2949
2950Release 2013f - 2013-09-24 23:37:36 -0700
2951
2952  Changes affecting near-future timestamps
2953
2954    Tocantins will very likely not observe DST starting this spring.
2955    (Thanks to Steffen Thorsen.)
2956
2957    Jordan will likely stay at UT +03 indefinitely, and will not fall
2958    back this fall.
2959
2960    Palestine will fall back at 00:00, not 01:00.  (Thanks to Steffen Thorsen.)
2961
2962  Changes affecting API
2963
2964    The types of the global variables 'timezone' and 'altzone' (if present)
2965    have been changed back to 'long'.  This is required for 'timezone'
2966    by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
2967    These variables were originally 'long' in the tz code, but were
2968    mistakenly changed to 'time_t' in 1987; nobody reported the
2969    incompatibility until now.  The difference matters on x32, where
2970    'long' is 32 bits and 'time_t' is 64.  (Thanks to Elliott Hughes.)
2971
2972  Changes affecting the build procedure
2973
2974    Avoid long strings in leapseconds.awk to work around a mawk bug.
2975    (Thanks to Cyril Baurand.)
2976
2977  Changes affecting documentation and commentary
2978
2979    New file 'NEWS' that contains release notes like this one.
2980
2981    Paraguay's law does not specify DST transition time; 00:00 is customary.
2982    (Thanks to Waldemar Villamayor-Venialbo.)
2983
2984    Minor capitalization fixes.
2985
2986  Changes affecting version-control only
2987
2988    The experimental GitHub repository now contains annotated and
2989    signed tags for recent releases, e.g., '2013e' for Release 2013e.
2990    Releases are tagged starting with 2012e; earlier releases were
2991    done differently, and tags would either not have a simple name or
2992    not exactly match what was released.
2993
2994    'make set-timestamps' is now simpler and a bit more portable.
2995
2996
2997Release 2013e - 2013-09-19 23:50:04 -0700
2998
2999  Changes affecting near-future timestamps
3000
3001    This year Fiji will start DST on October 27, not October 20.
3002    (Thanks to David Wheeler for the heads-up.)  For now, guess that
3003    Fiji will continue to spring forward the Sunday before the fourth
3004    Monday in October.
3005
3006  Changes affecting current and future time zone abbreviations
3007
3008    Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian
3009    time zone abbreviations since 1932.  (Thanks to George Ziegler,
3010    Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and
3011    Benny Lin.)  This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura,
3012    Asia/Makassar, and Asia/Pontianak.
3013
3014    Use ART (UT -03, standard time), rather than WARST (also -03, but
3015    daylight saving time) for San Luis, Argentina since 2009.
3016
3017  Changes affecting Godthåb timestamps after 2037 if version mismatch
3018
3019    Allow POSIX-like TZ strings where the transition time's hour can
3020    range from -167 through 167, instead of the POSIX-required 0
3021    through 24.  E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
3022    new Fiji rules.  This is a more-compact way to represent
3023    far-future timestamps for America/Godthab, America/Santiago,
3024    Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
3025    Pacific/Easter, and Pacific/Fiji.  Other zones are unaffected by
3026    this change.  (Derived from a suggestion by Arthur David Olson.)
3027
3028    Allow POSIX-like TZ strings where daylight saving time is in
3029    effect all year.  E.g., TZ='WART4WARST,J1/0,J365/25' for Western
3030    Argentina Summer Time all year.  This supports a more-compact way
3031    to represent the 2013d data for America/Argentina/San_Luis.
3032    Because of the change for San Luis noted above this change does not
3033    affect the current data.  (Thanks to Andrew Main (Zefram) for
3034    suggestions that improved this change.)
3035
3036    Where these two TZ changes take effect, there is a minor extension
3037    to the tz file format in that it allows new values for the
3038    embedded TZ-format string, and the tz file format version number
3039    has therefore been increased from 2 to 3 as a precaution.
3040    Version-2-based client code should continue to work as before for
3041    all timestamps before 2038.  Existing version-2-based client code
3042    (tzcode, GNU/Linux, Solaris) has been tested on version-3-format
3043    files, and typically works in practice even for timestamps after
3044    2037; the only known exception is America/Godthab.
3045
3046  Changes affecting timestamps before 1970
3047
3048    Pacific/Johnston is now a link to Pacific/Honolulu.  This corrects
3049    some errors before 1947.
3050
3051    Some zones have been turned into links, when they differ from existing
3052    zones only in older data entries that were likely invented or that
3053    differ only in LMT or transitions from LMT.  These changes affect
3054    only timestamps before 1943.  The affected zones are:
3055    Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
3056    America/Grenada, America/Guadeloupe, America/Marigot,
3057    America/Montserrat, America/St_Barthelemy, America/St_Kitts,
3058    America/St_Lucia, America/St_Thomas, America/St_Vincent,
3059    America/Tortola, and Europe/Vaduz.  (Thanks to Alois Treindl for
3060    confirming that the old Europe/Vaduz zone was wrong and the new
3061    link is better for WWII-era times.)
3062
3063    Change Kingston Mean Time from -5:07:12 to -5:07:11.  This affects
3064    America/Cayman, America/Jamaica and America/Grand_Turk timestamps
3065    from 1890 to 1912.
3066
3067    Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
3068    This affects Europe/Zurich timestamps from 1853 to 1894.  (Thanks
3069    to Alois Treindl.)
3070
3071    Change the date of the circa-1850 Zurich transition from 1849-09-12
3072    to 1853-07-16, overriding Shanks with data from Messerli about
3073    postal and telegraph time in Switzerland.
3074
3075  Changes affecting time zone abbreviations before 1970
3076
3077    For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932,
3078    as Jakarta was called Batavia back then.
3079
3080  Changes affecting API
3081
3082    The 'zic' command now outputs a dummy transition when far-future
3083    data can't be summarized using a TZ string, and uses a 402-year
3084    window rather than a 400-year window.  For the current data, this
3085    affects only the Asia/Tehran file.  It does not affect any of the
3086    timestamps that this file represents, so zdump outputs the same
3087    information as before.  (Thanks to Andrew Main (Zefram).)
3088
3089    The 'date' command has a new '-r' option, which lets you specify
3090    the integer time to display, a la FreeBSD.
3091
3092    The 'tzselect' command has two new options '-c' and '-n', which lets you
3093    select a zone based on latitude and longitude.
3094
3095    The 'zic' command's '-v' option now warns about constructs that
3096    require the new version-3 binary file format.  (Thanks to Arthur
3097    David Olson for the suggestion.)
3098
3099    Support for floating-point time_t has been removed.
3100    It was always dicey, and POSIX no longer requires it.
3101    (Thanks to Eric Blake for suggesting to the POSIX committee to
3102    remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
3103    Heninger, Arthur David Olson, and Alois Treindl, for reporting
3104    bugs and elucidating some of the corners of the old floating-point
3105    implementation.)
3106
3107    The signatures of 'offtime', 'timeoff', and 'gtime' have been
3108    changed back to the old practice of using 'long' to represent UT
3109    offsets.  This had been inadvertently and mistakenly changed to
3110    'int_fast32_t'.  (Thanks to Christos Zoulas.)
3111
3112    The code avoids undefined behavior on integer overflow in some
3113    more places, including gmtime, localtime, mktime and zdump.
3114
3115  Changes affecting the zdump utility
3116
3117    zdump now outputs "UT" when referring to Universal Time, not "UTC".
3118    "UTC" does not make sense for timestamps that predate the introduction
3119    of UTC, whereas "UT", a more-generic term, does.  (Thanks to Steve Allen
3120    for clarifying UT vs UTC.)
3121
3122  Data changes affecting behavior of tzselect and similar programs
3123
3124    Country code BQ is now called the more-common name "Caribbean Netherlands"
3125    rather than the more-official "Bonaire, St Eustatius & Saba".
3126
3127    Remove from zone.tab the names America/Montreal, America/Shiprock,
3128    and Antarctica/South_Pole, as they are equivalent to existing
3129    same-country-code zones for post-1970 timestamps.  The data entries for
3130    these names are unchanged, so the names continue to work as before.
3131
3132  Changes affecting code internals
3133
3134    zic -c now runs way faster on 64-bit hosts when given large numbers.
3135
3136    zic now uses vfprintf to avoid allocating and freeing some memory.
3137
3138    tzselect now computes the list of continents from the data,
3139    rather than have it hard-coded.
3140
3141    Minor changes pacify GCC 4.7.3 and GCC 4.8.1.
3142
3143  Changes affecting the build procedure
3144
3145    The 'leapseconds' file is now generated automatically from a
3146    new file 'leap-seconds.list', which is a copy of
3147    <ftp://ftp.nist.gov/pub/time/leap-seconds.list>
3148    A new source file 'leapseconds.awk' implements this.
3149    The goal is simplification of the future maintenance of 'leapseconds'.
3150
3151    When building the 'posix' or 'right' subdirectories, if the
3152    subdirectory would be a copy of the default subdirectory, it is
3153    now made a symbolic link if that is supported.  This saves about
3154    2 MB of file system space.
3155
3156    The links America/Shiprock and Antarctica/South_Pole have been
3157    moved to the 'backward' file.  This affects only nondefault builds
3158    that omit 'backward'.
3159
3160  Changes affecting version-control only
3161
3162    .gitignore now ignores 'date'.
3163
3164  Changes affecting documentation and commentary
3165
3166    Changes to the 'tzfile' man page
3167
3168      It now mentions that the binary file format may be extended in
3169      future versions by appending data.
3170
3171      It now refers to the 'zdump' and 'zic' man pages.
3172
3173    Changes to the 'zic' man page
3174
3175      It lists conditions that elicit a warning with '-v'.
3176
3177      It says that the behavior is unspecified when duplicate names
3178      are given, or if the source of one link is the target of another.
3179
3180      Its examples are updated to match the latest data.
3181
3182      The definition of white space has been clarified slightly.
3183      (Thanks to Michael Deckers.)
3184
3185    Changes to the 'Theory' file
3186
3187      There is a new section about the accuracy of the tz database,
3188      describing the many ways that errors can creep in, and
3189      explaining why so many of the pre-1970 timestamps are wrong or
3190      misleading (thanks to Steve Allen, Lester Caine, and Garrett
3191      Wollman for discussions that contributed to this).
3192
3193      The 'Theory' file describes LMT better (this follows a
3194      suggestion by Guy Harris).
3195
3196      It refers to the 2013 edition of POSIX rather than the 2004 edition.
3197
3198      It's mentioned that excluding 'backward' should not affect the
3199      other data, and it suggests at least one zone.tab name per
3200      inhabited country (thanks to Stephen Colebourne).
3201
3202      Some longstanding restrictions on names are documented, e.g.,
3203      'America/New_York' precludes 'America/New_York/Bronx'.
3204
3205      It gives more reasons for the 1970 cutoff.
3206
3207      It now mentions which time_t variants are supported, such as
3208      signed integer time_t.  (Thanks to Paul Goyette for reporting
3209      typos in an experimental version of this change.)
3210
3211      (Thanks to Philip Newton for correcting typos in these changes.)
3212
3213    Documentation and commentary is more careful to distinguish UT in
3214    general from UTC in particular.  (Thanks to Steve Allen.)
3215
3216    Add a better source for the Zurich 1894 transition.
3217    (Thanks to Pierre-Yves Berger.)
3218
3219    Update shapefile citations in tz-link.htm.  (Thanks to Guy Harris.)
3220
3221
3222Release 2013d - 2013-07-05 07:38:01 -0700
3223
3224  Changes affecting future timestamps:
3225
3226    Morocco's midsummer transitions this year are July 7 and August 10,
3227    not July 9 and August 8.  (Thanks to Andrew Paprocki.)
3228
3229    Israel now falls back on the last Sunday of October.
3230    (Thanks to Ephraim Silverberg.)
3231
3232  Changes affecting past timestamps:
3233
3234    Specify Jerusalem's location more precisely; this changes the pre-1880
3235    times by 2 s.
3236
3237  Changing affecting metadata only:
3238
3239    Fix typos in the entries for country codes BQ and SX.
3240
3241  Changes affecting code:
3242
3243    Rework the code to fix a bug with handling Australia/Macquarie on
3244    32-bit hosts (thanks to Arthur David Olson).
3245
3246    Port to platforms like NetBSD, where time_t can be wider than long.
3247
3248    Add support for testing time_t types other than the system's.
3249    Run 'make check_time_t_alternatives' to try this out.
3250    Currently, the tests fail for unsigned time_t;
3251    this should get fixed at some point.
3252
3253  Changes affecting documentation and commentary:
3254
3255    Deemphasize the significance of national borders.
3256
3257    Update the zdump man page.
3258
3259    Remove obsolete NOID comment (thanks to Denis Excoffier).
3260
3261    Update several URLs and comments in the web pages.
3262
3263    Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler).
3264
3265    Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka).
3266
3267
3268Release 2013c - 2013-04-19 16:17:40 -0700
3269
3270  Changes affecting current and future timestamps:
3271
3272    Palestine observed DST starting March 29, 2013.  (Thanks to
3273    Steffen Thorsen.)  From 2013 on, Gaza and Hebron both observe DST,
3274    with the predicted rules being the last Thursday in March at 24:00
3275    to the first Friday on or after September 21 at 01:00.
3276
3277    Assume that the recent change to Paraguay's DST rules is permanent,
3278    by moving the end of DST to the 4th Sunday in March every year.
3279    (Thanks to Carlos Raúl Perasso.)
3280
3281  Changes affecting past timestamps:
3282
3283    Fix some historical data for Palestine to agree with that of
3284    timeanddate.com, as follows:
3285
3286	  The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not
3287	  00:00 Apr 1.
3288
3289	  The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not
3290	  02:00.
3291
3292	  The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27.
3293
3294	  The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2.
3295
3296	  The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01.
3297
3298	  The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00.
3299
3300    Fix times of habitation for Macquarie to agree with the Tasmania
3301    Parks & Wildlife Service history, which indicates that permanent
3302    habitation was 1899-1919 and 1948 on.
3303
3304  Changing affecting metadata only:
3305
3306    Macquarie Island is politically part of Australia, not Antarctica.
3307    (Thanks to Tobias Conradi.)
3308
3309    Sort Macquarie more-consistently with other parts of Australia.
3310    (Thanks to Tim Parenti.)
3311
3312
3313Release 2013b - 2013-03-10 22:33:40 -0700
3314
3315  Changes affecting current and future timestamps:
3316
3317    Haiti uses US daylight-saving rules this year, and presumably future years.
3318    This changes timestamps starting today.  (Thanks to Steffen Thorsen.)
3319
3320    Paraguay will end DST on March 24 this year.
3321    (Thanks to Steffen Thorsen.)  For now, assume it's just this year.
3322
3323    Morocco does not observe DST during Ramadan;
3324    try to predict Ramadan in Morocco as best we can.
3325    (Thanks to Erik Homoet for the heads-up.)
3326
3327  Changes affecting commentary:
3328
3329    Update URLs in tz-link page.  Add URLs for webOS, BB10, iOS.
3330    Update URL for Solaris.  Mention Internet RFC 6557.
3331    Update Internet RFCs 2445->5545, 2822->5322.
3332    Switch from FTP to HTTP for Internet RFCs.
3333
3334
3335Release 2013a - 2013-02-27 09:20:35 -0800
3336
3337  Change affecting binary data format:
3338
3339    The zone offset at the end of version-2-format zone files is now
3340    allowed to be 24:00, as per POSIX.1-2008.  (Thanks to Arthur David Olson.)
3341
3342  Changes affecting current and future timestamps:
3343
3344    Chile's 2013 rules, and we guess rules for 2014 and later, will be
3345    the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC.
3346    (Thanks to Steffen Thorsen and Robert Elz.)
3347
3348    New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen.
3349    (Thanks to Tobias Conradi and Arthur David Olson.)
3350
3351  Many changes affect historical timestamps before 1940.
3352  These were deduced from: Milne J. Civil time. Geogr J. 1899
3353  Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.
3354
3355  Changes affecting the code:
3356
3357    Fix zic bug that mishandled Egypt's 2010 changes (this also affected
3358    the data).  (Thanks to Arthur David Olson.)
3359
3360    Fix localtime bug when time_t is unsigned and data files were generated
3361    by a signed time_t system.  (Thanks to Doug Bailey for reporting and
3362    to Arthur David Olson for fixing.)
3363
3364    Allow the email address for bug reports to be set by the packager.
3365    The default is tz@iana.org, as before.  (Thanks to Joseph S. Myers.)
3366
3367    Update HTML checking to be compatible with Ubuntu 12.10.
3368
3369    Check that files are a safe subset of ASCII.  At some point we may
3370    relax this requirement to a safe subset of UTF-8.  Without the
3371    check, some non-UTF-8 encodings were leaking into the distribution.
3372
3373  Commentary changes:
3374
3375    Restore a comment about copyright notices that was inadvertently deleted.
3376    (Thanks to Arthur David Olson.)
3377
3378    Improve the commentary about which districts observe what times
3379    in Russia.  (Thanks to Oscar van Vlijmen and Arthur David Olson.)
3380
3381    Add web page links to tz.js.
3382
3383    Add "Run by the Monkeys" to tz-art.  (Thanks to Arthur David Olson.)
3384
3385
3386Release 2012j - 2012-11-12 18:34:49 -0800
3387
3388  Libya moved to CET this weekend, but with DST planned next year.
3389  (Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.)
3390
3391  Signatures now have the extension .asc, not .sign, as that's more
3392  standard.  (Thanks to Phil Pennock.)
3393
3394  The output of 'zdump --version', and of 'zic --version', now
3395  uses a format that is more typical for --version.
3396  (Thanks to Joseph S. Myers.)
3397
3398  The output of 'tzselect --help', 'zdump --help', and 'zic --help'
3399  now uses tz@iana.org rather than the old elsie address.
3400
3401  zic -v now complains about abbreviations that are less than 3
3402  or more than 6 characters, as per Posix.  Formerly, it checked
3403  for abbreviations that were more than 3.
3404
3405  'make public' no longer puts its temporary directory under /tmp,
3406  and uses the just-built zic rather than the system zic.
3407
3408  Various fixes to documentation and commentary.
3409
3410
3411Release 2012i - 2012-11-03 12:57:09 -0700
3412
3413  Cuba switches from DST tomorrow at 01:00.  (Thanks to Steffen Thorsen.)
3414
3415  Linker flags can now be specified via LDFLAGS.
3416  AWK now defaults to 'awk', not 'nawk'.
3417  The shell in tzselect now defaults to /bin/bash, but this can
3418  be overridden by specifying KSHELL.
3419  The main web page now mentions the unofficial GitHub repository.
3420  (Thanks to Mike Frysinger.)
3421
3422  Tarball signatures can now be built by running 'make signatures'.
3423  There are also new makefile rules 'tarballs', 'check_public', and
3424  separate makefile rules for each tarball and signature file.
3425  A few makefile rules are now more portable to strict POSIX.
3426
3427  The main web page now lists the canonical IANA URL.
3428
3429
3430Release 2012h - 2012-10-26 22:49:10 -0700
3431
3432  Bahia no longer has DST.  (Thanks to Kelley Cook.)
3433
3434  Tocantins has DST.  (Thanks to Rodrigo Severo.)
3435
3436  Israel has new DST rules next year.  (Thanks to Ephraim Silverberg.)
3437
3438  Jordan stays on DST this winter.  (Thanks to Steffen Thorsen.)
3439
3440  Web page updates.
3441
3442  More C modernization, except that at Arthur David Olson's suggestion
3443  the instances of 'register' were kept.
3444
3445
3446Release 2012g - 2012-10-17 20:59:45 -0700
3447
3448  Samoa fall 2012 and later.  (Thanks to Nicholas Pereira and Robert Elz.)
3449
3450  Palestine fall 2012.  (Thanks to Steffen Thorsen.)
3451
3452  Assume C89.
3453
3454  To attack the version-number problem, this release ships the file
3455  'Makefile' (which contains the release number) in both the tzcode and
3456  the tzdata tarballs.  The two Makefiles are identical, and should be
3457  identical in any matching pair of tarballs, so it shouldn't matter
3458  which order you extract the tarballs.  Perhaps we can come up with a
3459  better version-number scheme at some point; this scheme does have the
3460  virtue of not adding more files.
3461
3462
3463Release 2012f - 2012-09-12 23:17:03 -0700
3464
3465  * australasia (Pacific/Fiji): Fiji DST is October 21 through January
3466    20 this year.  (Thanks to Steffen Thorsen.)
3467
3468
3469Release 2012e - 2012-08-02 20:44:55 -0700
3470
3471  * australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14.
3472    (Thanks to Steffen Thorsen.)
3473
3474  * Use a single version number for both code and data.
3475
3476  * .gitignore: New file.
3477
3478  * Remove trailing white space.
3479
3480
3481Release code2012c-data2012d - 2012-07-19 16:35:33 -0700
3482
3483  Changes for Morocco's timestamps, which take effect in a couple of
3484  hours, along with infrastructure changes to accommodate how the tz
3485  code and data are released on IANA.
3486
3487
3488Release data2012c - 2012-03-27 12:17:25 -0400
3489
3490  africa
3491	Summer time changes for Morocco (to start late April 2012)
3492
3493  asia
3494	Changes for 2012 for Gaza & the West Bank (Hebron) and Syria
3495
3496  northamerica
3497	Haiti following US/Canada rules for 2012 (and we're assuming,
3498	for now anyway, for the future).
3499
3500
3501Release 2012b - 2012-03-02 12:29:15 +0700
3502
3503  There is just one change to tzcode2012b (compared with 2012a):
3504  the Makefile that was accidentally included with 2012a has been
3505  replaced with the version that should have been there, which is
3506  identical with the previous version (from tzcode2011i).
3507
3508  There are just two changes in tzdata2012b compared with 2012a.
3509
3510  Most significantly, summer time in Cuba has been delayed 3 weeks
3511  (now starts April 1 rather than March 11).   Since Mar 11 (the old start
3512  date, as listed in 2012a) is just a little over a week away, this
3513  change is urgent.
3514
3515  Less importantly, an excess tab in one of the changes in zone.tab
3516  in 2012a has been removed.
3517
3518
3519Release 2012a - 2012-03-01 18:28:10 +0700
3520
3521  The changes in tzcode2012a (compared to the previous version, 2011i)
3522  are entirely to the README and tz-art.htm and tz-link.htm files, if
3523  none of those concern you, you can ignore the code update.  The changes
3524  reflect the changed addresses for the mailing list and the code and
3525  data distribution points & methods (and a link to DateTime::TimeZone::Tzfile
3526  has been added to tz-link.htm).
3527
3528  In tzdata2012a (compared to the previous release, which was 2011n)
3529  the major changes are:
3530	Chile 2011/2012 and 2012/2013 summer time date adjustments.
3531	Falkland Islands onto permanent summer time (we're assuming for the
3532		foreseeable future, though 2012 is all we're fairly certain of.)
3533	Armenia has abolished Summer Time.
3534	Tokelau jumped the International Date Line back last December
3535		(just the same as their near neighbour, Samoa).
3536	America/Creston is a new zone for a small area of British Columbia
3537	There will be a leapsecond 2012-06-30 23:59:60 UTC.
3538
3539  Other minor changes are:
3540	Corrections to 1918 Canadian summer time end dates.
3541	Updated URL for UK time zone history (in comments)
3542	A few typos in Le Corre's list of free French place names (comments)
3543
3544
3545Release data2011n - 2011-10-30 14:57:54 +0700
3546
3547  There are three changes of note - most urgently, Cuba (America/Havana)
3548  has extended summer time by two weeks, now to end on Nov 13, rather than
3549  the (already past) Oct 30.   Second, the Pridnestrovian Moldavian Republic
3550  (Europe/Tiraspol) decided not to split from the rest of Moldova after
3551  all, and consequently that zone has been removed (again) and reinstated
3552  in the "backward" file as a link to Europe/Chisinau.   And third, the
3553  end date for Fiji's summer time this summer was moved forward from the
3554  earlier planned Feb 26, to Jan 22.
3555
3556  Apart from that, Moldova (MD) returns to a single entry in zone.tab
3557  (and the incorrect syntax that was in the 2011m version of that file
3558  is so fixed - it would have been fixed in a different way had this
3559  change not happened - that's the "missing" sccs version id).
3560
3561
3562Release data2011m - 2011-10-24 21:42:16 +0700
3563
3564  In particular, the typos in comments in the data (2011-11-17 should have
3565  been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that
3566  Tim Parenti noted) have been fixed, and the change for Ukraine has been
3567  made in all 4 Ukrainian zones, rather than just Kiev (again, thanks to
3568  Tim Parenti, and also Denys Gavrysh)
3569
3570  In addition, I added Europe/Tiraspol to zone.tab.
3571
3572  This time, all the files have new version numbers...  (including the files
3573  otherwise unchanged in 2011m that were changed in 2011l but didn't get new
3574  version numbers there...)
3575
3576
3577Release data2011l - 2011-10-10 11:15:43 +0700
3578
3579  There are just 2 changes that cause different generated tzdata files from
3580  zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil
3581  is included, but commented out.  Compared with the diff I sent out last week,
3582  this version also includes attributions for the sources for the changes
3583  (in much the same format as ado used, but the html tags have not been
3584  checked, verified, or used in any way at all, so if there are errors there,
3585  please let me know.)
3586
3587
3588Release data2011k - 2011-09-20 17:54:03 -0400
3589
3590  [not summarized]
3591
3592
3593Release data2011j - 2011-09-12 09:22:49 -0400
3594
3595  (contemporary changes for Samoa; past changes for Kenya, Uganda, and
3596  Tanzania); there are also two spelling corrections to comments in
3597  the australasia file (with thanks to Christos Zoulas).
3598
3599
3600Release 2011i - 2011-08-29 05:56:32 -0400
3601
3602  [not summarized]
3603
3604
3605Release data2011h - 2011-06-15 18:41:48 -0400
3606
3607  Russia and Curaçao changes
3608
3609
3610Release 2011g - 2011-04-25 09:07:22 -0400
3611
3612  update the rules for Egypt to reflect its abandonment of DST this year
3613
3614
3615Release 2011f - 2011-04-06 17:14:53 -0400
3616
3617  [not summarized]
3618
3619
3620Release 2011e - 2011-03-31 16:04:38 -0400
3621
3622  Morocco, Chile, and tz-link changes
3623
3624
3625Release 2011d - 2011-03-14 09:18:01 -0400
3626
3627  changes that impact present-day timestamps in Cuba, Samoa, and Turkey
3628
3629
3630Release 2011c - 2011-03-07 09:30:09 -0500
3631
3632  These do affect current timestamps in Chile and Annette Island, Canada.
3633
3634
3635Release 2011b - 2011-02-07 08:44:50 -0500
3636
3637  [not summarized]
3638
3639
3640Release 2011a - 2011-01-24 10:30:16 -0500
3641
3642  [not summarized]
3643
3644
3645Release data2010o - 2010-11-01 09:18:23 -0400
3646
3647  change to the end of DST in Fiji in 2011
3648
3649
3650Release 2010n - 2010-10-25 08:19:17 -0400
3651
3652  [not summarized]
3653
3654
3655Release 2010m - 2010-09-27 09:24:48 -0400
3656
3657  Hong Kong, Vostok, and zic.c changes
3658
3659
3660Release 2010l - 2010-08-16 06:57:25 -0400
3661
3662  [not summarized]
3663
3664
3665Release 2010k - 2010-07-26 10:42:27 -0400
3666
3667  [not summarized]
3668
3669
3670Release 2010j - 2010-05-10 09:07:48 -0400
3671
3672  changes for Bahía de Banderas and for version naming
3673
3674
3675Release data2010i - 2010-04-16 18:50:45 -0400
3676
3677  the end of DST in Morocco on 2010-08-08
3678
3679
3680Release data2010h - 2010-04-05 09:58:56 -0400
3681
3682  [not summarized]
3683
3684
3685Release data2010g - 2010-03-24 11:14:53 -0400
3686
3687  [not summarized]
3688
3689
3690Release 2010f - 2010-03-22 09:45:46 -0400
3691
3692  [not summarized]
3693
3694
3695Release data2010e - 2010-03-08 14:24:27 -0500
3696
3697  corrects the Dhaka bug found by Danvin Ruangchan
3698
3699
3700Release data2010d - 2010-03-06 07:26:01 -0500
3701
3702  [not summarized]
3703
3704
3705Release 2010c - 2010-03-01 09:20:58 -0500
3706
3707  changes including KRE's suggestion for earlier initialization of
3708  "goahead" and "goback" structure elements
3709
3710
3711Release code2010a - 2010-02-16 10:40:04 -0500
3712
3713  [not summarized]
3714
3715
3716Release data2010b - 2010-01-20 12:37:01 -0500
3717
3718  Mexico changes
3719
3720
3721Release data2010a - 2010-01-18 08:30:04 -0500
3722
3723  changes to Dhaka
3724
3725
3726Release data2009u - 2009-12-26 08:32:28 -0500
3727
3728  changes to DST in Bangladesh
3729
3730
3731Release 2009t - 2009-12-21 13:24:27 -0500
3732
3733  [not summarized]
3734
3735
3736Release data2009s - 2009-11-14 10:26:32 -0500
3737
3738  (cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change
3739
3740
3741Release 2009r - 2009-11-09 10:10:31 -0500
3742
3743  "antarctica" and "tz-link.htm" changes
3744
3745
3746Release 2009q - 2009-11-02 09:12:40 -0500
3747
3748  with two corrections as reported by Eric Muller and Philip Newton
3749
3750
3751Release data2009p - 2009-10-23 15:05:27 -0400
3752
3753  Argentina (including San Luis) changes (with the correction from
3754  Mariano Absatz)
3755
3756
3757Release data2009o - 2009-10-14 16:49:38 -0400
3758
3759  Samoa (commentary only), Pakistan, and Bangladesh changes
3760
3761
3762Release data2009n - 2009-09-22 15:13:38 -0400
3763
3764  added commentary for Argentina and a change to the end of DST in
3765  2009 in Pakistan
3766
3767
3768Release data2009m - 2009-09-03 10:23:43 -0400
3769
3770  Samoa and Palestine changes
3771
3772
3773Release data2009l - 2009-08-14 09:13:07 -0400
3774
3775  Samoa (comments only) and Egypt
3776
3777
3778Release 2009k - 2009-07-20 09:46:08 -0400
3779
3780  [not summarized]
3781
3782
3783Release data2009j - 2009-06-15 06:43:59 -0400
3784
3785  Bangladesh change (with a short turnaround since the DST change is
3786  impending)
3787
3788
3789Release 2009i - 2009-06-08 09:21:22 -0400
3790
3791  updating for DST in Bangladesh this year
3792
3793
3794Release 2009h - 2009-05-26 09:19:14 -0400
3795
3796  [not summarized]
3797
3798
3799Release data2009g - 2009-04-20 16:34:07 -0400
3800
3801  Cairo
3802
3803
3804Release data2009f - 2009-04-10 11:00:52 -0400
3805
3806  correct DST in Pakistan
3807
3808
3809Release 2009e - 2009-04-06 09:08:11 -0400
3810
3811  [not summarized]
3812
3813
3814Release 2009d - 2009-03-23 09:38:12 -0400
3815
3816  Morocco, Tunisia, Argentina, and American Astronomical Society changes
3817
3818
3819Release data2009c - 2009-03-16 09:47:51 -0400
3820
3821  change to the start of Cuban DST
3822
3823
3824Release 2009b - 2009-02-09 11:15:22 -0500
3825
3826  [not summarized]
3827
3828
3829Release 2009a - 2009-01-21 10:09:39 -0500
3830
3831  [not summarized]
3832
3833
3834Release data2008i - 2008-10-21 12:10:25 -0400
3835
3836  southamerica and zone.tab files, with Argentina DST rule changes and
3837  United States zone reordering and recommenting
3838
3839
3840Release 2008h - 2008-10-13 07:33:56 -0400
3841
3842  [not summarized]
3843
3844
3845Release 2008g - 2008-10-06 09:03:18 -0400
3846
3847  Fix a broken HTML anchor and update Brazil's DST transitions;
3848  there's also a slight reordering of information in tz-art.htm.
3849
3850
3851Release data2008f - 2008-09-09 22:33:26 -0400
3852
3853  [not summarized]
3854
3855
3856Release 2008e - 2008-07-28 14:11:17 -0400
3857
3858  changes by Arthur David Olson and Jesper Nørgaard Welen
3859
3860
3861Release data2008d - 2008-07-07 09:51:38 -0400
3862
3863  changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo
3864
3865
3866Release data2008c - 2008-05-19 17:48:03 -0400
3867
3868  Pakistan, Morocco, and Mongolia
3869
3870
3871Release data2008b - 2008-03-24 08:30:59 -0400
3872
3873  including renaming Asia/Calcutta to Asia/Kolkata, with a backward
3874  link provided
3875
3876
3877Release 2008a - 2008-03-08 05:42:16 -0500
3878
3879  [not summarized]
3880
3881
3882Release 2007k - 2007-12-31 10:25:22 -0500
3883
3884  most importantly, changes to the "southamerica" file based on
3885  Argentina's readoption of daylight saving time
3886
3887
3888Release 2007j - 2007-12-03 09:51:01 -0500
3889
3890  1. eliminate the "P" (parameter) macro;
3891
3892  2. the "noncontroversial" changes circulated on the time zone
3893  mailing list (less the changes to "logwtmp.c");
3894
3895  3. eliminate "too many transition" errors when "min" is used in time
3896  zone rules;
3897
3898  4. changes by Paul Eggert (including updated information for Venezuela).
3899
3900
3901Release data2007i - 2007-10-30 10:28:11 -0400
3902
3903  changes for Cuba and Syria
3904
3905
3906Release 2007h - 2007-10-01 10:05:51 -0400
3907
3908  changes by Paul Eggert, as well as an updated link to the ICU
3909  project in tz-link.htm
3910
3911
3912Release 2007g - 2007-08-20 10:47:59 -0400
3913
3914  changes by Paul Eggert
3915
3916  The "leapseconds" file has been updated to incorporate the most
3917  recent International Earth Rotation and Reference Systems Service
3918  (IERS) bulletin.
3919
3920  There's an addition to tz-art.htm regarding the television show "Medium".
3921
3922
3923Release 2007f - 2007-05-07 10:46:46 -0400
3924
3925  changes by Paul Eggert (including Haiti, Turks and Caicos, and New
3926  Zealand)
3927
3928  changes to zic.c to allow hour values greater than 24 (along with
3929  Paul's improved time value overflow checking)
3930
3931
3932Release 2007e - 2007-04-02 10:11:52 -0400
3933
3934  Syria and Honduras changes by Paul Eggert
3935
3936  zic.c variable renaming changes by Arthur David Olson
3937
3938
3939Release 2007d - 2007-03-20 08:48:30 -0400
3940
3941  changes by Paul Eggert
3942
3943  the elimination of white space at the ends of lines
3944
3945
3946Release 2007c - 2007-02-26 09:09:37 -0500
3947
3948  changes by Paul Eggert
3949
3950
3951Release 2007b - 2007-02-12 09:34:20 -0500
3952
3953  Paul Eggert's proposed change to the quotation handling logic in zic.c.
3954
3955  changes to the commentary in "leapseconds" reflecting the IERS
3956  announcement that there is to be no positive leap second at the end
3957  of June 2007.
3958
3959
3960Release 2007a - 2007-01-08 12:28:29 -0500
3961
3962  changes by Paul Eggert
3963
3964  Derick Rethan's Asmara change
3965
3966  Oscar van Vlijmen's Easter Island local mean time change
3967
3968  symbolic link changes
3969
3970
3971Release 2006p - 2006-11-27 08:54:27 -0500
3972
3973  changes by Paul Eggert
3974
3975
3976Release 2006o - 2006-11-06 09:18:07 -0500
3977
3978  changes by Paul Eggert
3979
3980
3981Release 2006n - 2006-10-10 11:32:06 -0400
3982
3983  changes by Paul Eggert
3984
3985
3986Release 2006m - 2006-10-02 15:32:35 -0400
3987
3988  changes for Uruguay, Palestine, and Egypt by Paul Eggert
3989
3990  (minimalist) changes to zic.8 to clarify "until" information
3991
3992
3993Release data2006l - 2006-09-18 12:58:11 -0400
3994
3995  Paul's best-effort work on this coming weekend's Egypt time change
3996
3997
3998Release 2006k - 2006-08-28 12:19:09 -0400
3999
4000  changes by Paul Eggert
4001
4002
4003Release 2006j - 2006-08-21 09:56:32 -0400
4004
4005  changes by Paul Eggert
4006
4007
4008Release code2006i - 2006-08-07 12:30:55 -0400
4009
4010  localtime.c fixes
4011
4012  Ken Pizzini's conversion script
4013
4014
4015Release code2006h - 2006-07-24 09:19:37 -0400
4016
4017  adds public domain notices to four files
4018
4019  includes a fix for transition times being off by a second
4020
4021  adds a new recording to the "arts" file (information courtesy Colin Bowern)
4022
4023
4024Release 2006g - 2006-05-08 17:18:09 -0400
4025
4026  northamerica changes by Paul Eggert
4027
4028
4029Release 2006f - 2006-05-01 11:46:00 -0400
4030
4031  a missing version number problem is fixed (with thanks to Bradley
4032  White for catching the problem)
4033
4034
4035Release 2006d - 2006-04-17 14:33:43 -0400
4036
4037  changes by Paul Eggert
4038
4039  added new items to tz-arts.htm that were found by Paul
4040
4041
4042Release 2006c - 2006-04-03 10:09:32 -0400
4043
4044  two sets of data changes by Paul Eggert
4045
4046  a fencepost error fix in zic.c
4047
4048  changes to zic.c and the "europe" file to minimize differences
4049  between output produced by the old 32-bit zic and the new 64-bit
4050  version
4051
4052
4053Release 2006b - 2006-02-20 10:08:18 -0500
4054  [tz32code2006b + tz64code2006b + tzdata2006b]
4055
4056  64-bit code
4057
4058  All SCCS IDs were bumped to "8.1" for this release.
4059
4060
4061Release 2006a - 2006-01-30 08:59:31 -0500
4062
4063  changes by Paul Eggert (in particular, Indiana time zone moves)
4064
4065  an addition to the zic manual page to describe how special-case
4066  transitions are handled
4067
4068
4069Release 2005r - 2005-12-27 09:27:13 -0500
4070
4071  Canadian changes by Paul Eggert
4072
4073  They also add "<pre>" directives to time zone data files and reflect
4074  changes to warning message logic in "zdump.c" (but with calls to
4075  "gettext" kept unbundled at the suggestion of Ken Pizzini).
4076
4077
4078Release 2005q - 2005-12-13 09:17:09 -0500
4079
4080  Nothing earth-shaking here:
4081	1.  Electronic mail addresses have been removed.
4082	2.  Casts of the return value of exit have been removed.
4083	3.  Casts of the argument of is.* macros have been added.
4084	4.  Indentation in one section of zic.c has been fixed.
4085	5.  References to dead URLs in the data files have been dealt with.
4086
4087
4088Release 2005p - 2005-12-05 10:30:53 -0500
4089
4090  "systemv", "tz-link.htm", and "zdump.c" changes
4091  (less the casts of arguments to the is* macros)
4092
4093
4094Release 2005o - 2005-11-28 10:55:26 -0500
4095
4096  Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert
4097
4098  zdump.c lint fixes by Arthur David Olson
4099
4100
4101Release 2005n - 2005-10-03 09:44:09 -0400
4102
4103  changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan
4104  et al. changes)
4105
4106
4107Release 2005m - 2005-08-29 12:15:40 -0400
4108
4109  changes by Paul Eggert (with a small tweak to the tz-art change)
4110
4111  a declaration of an unused variable has been removed from zdump.c
4112
4113
4114Release 2005l - 2005-08-22 12:06:39 -0400
4115
4116  changes by Paul Eggert
4117
4118  overflow/underflow checks by Arthur David Olson, minus changes to
4119  the "Theory" file about the pending addition of 64-bit data (I grow
4120  less confident of the changes being accepted with each passing day,
4121  and the changes no longer increase the data files nine-fold--there's
4122  less than a doubling in size by my local Sun's reckoning)
4123
4124
4125Release 2005k - 2005-07-14 14:14:24 -0400
4126
4127  The "leapseconds" file has been edited to reflect the recently
4128  announced leap second at the end of 2005.
4129
4130  I've also deleted electronic mail addresses from the files as an
4131  anti-spam measure.
4132
4133
4134Release 2005j - 2005-06-13 14:34:13 -0400
4135
4136  These reflect changes to limit the length of time zone abbreviations
4137  and the characters used in those abbreviations.
4138
4139  There are also changes to handle POSIX-style "quoted" timezone
4140  environment variables.
4141
4142  The changes were circulated on the time zone mailing list; the only
4143  change since then was the removal of a couple of minimum-length of
4144  abbreviation checks.
4145
4146
4147Release data2005i - 2005-04-21 15:04:16 -0400
4148
4149  changes (most importantly to Nicaragua and Haiti) by Paul Eggert
4150
4151
4152Release 2005h - 2005-04-04 11:24:47 -0400
4153
4154  changes by Paul Eggert
4155
4156  minor changes to Makefile and zdump.c to produce more useful output
4157  when doing a "make typecheck"
4158
4159
4160Release 2005g - 2005-03-14 10:11:21 -0500
4161
4162  changes by Paul Eggert (a change to current DST rules in Uruguay and
4163  an update to a link to time zone software)
4164
4165
4166Release 2005f - 2005-03-01 08:45:32 -0500
4167
4168  data and documentation changes by Paul Eggert
4169
4170
4171Release 2005e - 2005-02-10 15:59:44 -0500
4172
4173  [not summarized]
4174
4175
4176Release code2005d - 2005-01-31 09:21:47 -0500
4177
4178  make zic complain about links to links if the -v flag is used
4179
4180  have "make public" do more code checking
4181
4182  add an include to "localtime.c" for the benefit of gcc systems
4183
4184
4185Release 2005c - 2005-01-17 18:36:29 -0500
4186
4187  get better results when mktime runs on a system where time_t is double
4188
4189  changes to the data files (most importantly to Paraguay)
4190
4191
4192Release 2005b - 2005-01-10 09:19:54 -0500
4193
4194  Get localtime and gmtime working on systems with exotic time_t types.
4195
4196  Update the leap second commentary in the "leapseconds" file.
4197
4198
4199Release 2005a - 2005-01-01 13:13:44 -0500
4200
4201  [not summarized]
4202
4203
4204Release code2004i - 2004-12-14 13:42:58 -0500
4205
4206  Deal with systems where time_t is unsigned.
4207
4208
4209Release code2004h - 2004-12-07 11:40:18 -0500
4210
4211  64-bit-time_t changes
4212
4213
4214Release 2004g - 2004-11-02 09:06:01 -0500
4215
4216  update to Cuba (taking effect this weekend)
4217
4218  other changes by Paul Eggert
4219
4220  correction of the spelling of Oslo
4221
4222  changed versions of difftime.c and private.h
4223
4224
4225Release code2004f - 2004-10-21 10:25:22 -0400
4226
4227  Cope with wide-ranging tm_year values.
4228
4229
4230Release 2004e - 2004-10-11 14:47:21 -0400
4231
4232  Brazil/Argentina/Israel changes by Paul Eggert
4233
4234  changes to tz-link.htm by Paul
4235
4236  one small fix to Makefile
4237
4238
4239Release 2004d - 2004-09-22 08:27:29 -0400
4240
4241  Avoid overflow problems when TM_YEAR_BASE is added to an integer.
4242
4243
4244Release 2004c - 2004-08-11 12:06:26 -0400
4245
4246  asctime-related changes
4247
4248  (variants of) some of the documentation changes suggested by Paul Eggert
4249
4250
4251Release 2004b - 2004-07-19 14:33:35 -0400
4252
4253  data changes by Paul Eggert - most importantly, updates for Argentina
4254
4255
4256Release 2004a - 2004-05-27 12:00:47 -0400
4257
4258  changes by Paul Eggert
4259
4260  Handle DST transitions that occur at the end of a month in some
4261  years but at the start of the following month in other years.
4262
4263  Add a copy of the correspondence that's the basis for claims about
4264  DST in the Navajo Nation.
4265
4266
4267Release 2003e - 2003-12-15 09:36:47 -0500
4268
4269  changes by Arthur David Olson (primarily code changes)
4270
4271  changes by Paul Eggert (primarily data changes)
4272
4273  minor changes to "Makefile" and "northamerica" (in the latter case,
4274  optimization of the "Toronto" rules)
4275
4276
4277Release 2003d - 2003-10-06 09:34:44 -0400
4278
4279  changes by Paul Eggert
4280
4281
4282Release 2003c - 2003-09-16 10:47:05 -0400
4283
4284  Fix bad returns in zic.c's inleap function.
4285  Thanks to Bradley White for catching the problem!
4286
4287
4288Release 2003b - 2003-09-16 07:13:44 -0400
4289
4290  Add a "--version" option (and documentation) to the zic and zdump commands.
4291
4292  changes to overflow/underflow checking in zic
4293
4294  a localtime typo fix.
4295
4296  Update the leapseconds and tz-art.htm files.
4297
4298
4299Release 2003a - 2003-03-24 09:30:54 -0500
4300
4301  changes by Paul Eggert
4302
4303  a few additions and modifications to the tz-art.htm file
4304
4305
4306Release 2002d - 2002-10-15 13:12:42 -0400
4307
4308  changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab
4309
4310  There's also a new time zone quote in "tz-art.htm".
4311
4312
4313Release 2002c - 2002-04-04 11:55:20 -0500
4314
4315  changes by Paul Eggert
4316
4317  Change zic.c to avoid creating symlinks to files that don't exist.
4318
4319
4320Release 2002b - 2002-01-28 12:56:03 -0500
4321
4322  [These change notes are for Release 2002a, which was corrupted.
4323  2002b was a corrected version of 2002a.]
4324
4325  changes by Paul Eggert
4326
4327  Update the "leapseconds" file to note that there'll be no leap
4328  second at the end of June, 2002.
4329
4330  Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone.
4331
4332  Change to "difftime.c" to avoid sizeof problems.
4333
4334
4335Release 2001d - 2001-10-09 13:31:32 -0400
4336
4337  changes by Paul Eggert
4338
4339
4340Release 2001c - 2001-06-05 13:59:55 -0400
4341
4342  changes by Paul Eggert and Andrew Brown
4343
4344
4345Release 2001b - 2001-04-05 16:44:38 -0400
4346
4347  changes by Paul Eggert (modulo jnorgard's typo fix)
4348
4349  tz-art.htm has been HTMLified.
4350
4351
4352Release 2001a - 2001-03-13 12:57:44 -0500
4353
4354  changes by Paul Eggert
4355
4356  An addition to the "leapseconds" file: comments with the text of the
4357  latest IERS leap second notice.
4358
4359  Trailing white space has been removed from data file lines, and
4360  repeated spaces in "Rule Jordan" lines in the "asia" file have been
4361  converted to tabs.
4362
4363
4364Release 2000h - 2000-12-14 15:33:38 -0500
4365
4366  changes by Paul Eggert
4367
4368  one typo fix in the "art" file
4369
4370  With providence, this is the last update of the millennium.
4371
4372
4373Release 2000g - 2000-10-10 11:35:22 -0400
4374
4375  changes by Paul Eggert
4376
4377  correction of John Mackin's name submitted by Robert Elz
4378
4379  Garry Shandling's Daylight Saving Time joke (!?!) from the recent
4380  Emmy Awards broadcast.
4381
4382
4383Release 2000f - 2000-08-10 09:31:58 -0400
4384
4385  changes by Paul Eggert
4386
4387  Added information in "tz-art.htm" on a Seinfeld reference to DST.
4388
4389  Error checking and messages in the "yearistype" script have been
4390  improved.
4391
4392
4393Release 2000e - 2000-07-31 09:27:54 -0400
4394
4395  data changes by Paul Eggert
4396
4397  a change to the default value of the defined constant HAVE_STRERROR
4398
4399  the addition of a Dave Barry quote on DST to the tz-arts file
4400
4401
4402Release 2000d - 2000-04-20 15:43:04 -0400
4403
4404  changes to the documentation and code of strftime for C99 conformance
4405
4406  a bug fix for date.c
4407
4408  These are based on (though modified from) changes by Paul Eggert.
4409
4410
4411Release 2000c - 2000-03-04 10:31:43 -0500
4412
4413  changes by Paul Eggert
4414
4415
4416Release 2000b - 2000-02-21 12:16:29 -0500
4417
4418  changes by Paul Eggert and Joseph Myers
4419
4420  modest tweaks to the tz-art.htm and tz-link.htm files
4421
4422
4423Release 2000a - 2000-01-18 09:21:26 -0500
4424
4425  changes by Paul Eggert
4426
4427  The two hypertext documents have also been renamed.
4428
4429
4430Release code1999i-data1999j - 1999-11-15 18:43:22 -0500
4431
4432  Paul Eggert's changes
4433
4434  additions to the "zic" manual page and the "Arts.htm" file
4435
4436
4437Release code1999h-data1999i - 1999-11-08 14:55:21 -0500
4438
4439  [not summarized]
4440
4441
4442Release data1999h - 1999-10-07 03:50:29 -0400
4443
4444  changes by Paul Eggert to "europe" (most importantly, fixing
4445  Lithuania and Estonia)
4446
4447
4448Release 1999g - 1999-09-28 11:06:18 -0400
4449
4450  data changes by Paul Eggert (most importantly, the change for
4451  Lebanon that buys correctness for this coming Sunday)
4452
4453  The "code" file contains changes to "Makefile" and "checktab.awk" to
4454  allow better checking of time zone files before they are published.
4455
4456
4457Release 1999f - 1999-09-23 09:48:14 -0400
4458
4459  changes by Arthur David Olson and Paul Eggert
4460
4461
4462Release 1999e - 1999-08-17 15:20:54 -0400
4463
4464  changes circulated by Paul Eggert, although the change to handling
4465  of DST-specifying timezone names has been commented out for now
4466  (search for "XXX" in "localtime.c" for details).  These files also
4467  do not make any changes to the start of DST in Brazil.
4468
4469  In addition to Paul's changes, there are updates to "Arts.htm" and
4470  cleanups of URLs.
4471
4472
4473Release 1999d - 1999-03-30 11:31:07 -0500
4474
4475  changes by Paul Eggert
4476
4477  The Makefile's "make public" rule has also been changed to do a test
4478  compile of each individual time zone data file (which should help
4479  avoid problems such as the one we had with Nicosia).
4480
4481
4482Release 1999c - 1999-03-25 09:47:47 -0500
4483
4484  changes by Paul Eggert, most importantly the change for Chile.
4485
4486
4487Release 1999b - 1999-02-01 17:51:44 -0500
4488
4489  changes by Paul Eggert
4490
4491  code changes (suggested by Mani Varadarajan, mani at be.com) for
4492  correct handling of symbolic links when building using a relative directory
4493
4494  code changes to generate correct messages for failed links
4495
4496  updates to the URLs in Arts.htm
4497
4498
4499Release 1999a - 1999-01-19 16:20:29 -0500
4500
4501  error message internationalizations and corrections in zic.c and
4502  zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz,
4503  to whom thanks!)
4504
4505
4506Release code1998h-data1998i - 1998-10-01 09:56:10 -0400
4507
4508  changes for Brazil, Chile, and Germany
4509
4510  support for use of "24:00" in the input files for the time zone compiler
4511
4512
4513Release code1998g-data1998h - 1998-09-24 10:50:28 -0400
4514
4515  changes by Paul Eggert
4516
4517  correction to a define in the "private.h" file
4518
4519
4520Release data1998g - 1998-08-11 03:28:35 -0000
4521  [tzdata1998g.tar.gz is missing!]
4522
4523  Lithuanian change provided by mgedmin at pub.osf.it
4524
4525  Move creation of the GMT link with Etc/GMT to "etcetera" (from
4526  "backward") to ensure that the GMT file is created even where folks
4527  don't want the "backward" links (as suggested by Paul Eggert).
4528
4529
4530Release data1998f - 1998-07-20 13:50:00 -0000
4531  [tzdata1998f.tar.gz is missing!]
4532
4533  Update the "leapseconds" file to include the newly-announced
4534  insertion at the end of 1998.
4535
4536
4537Release code1998f - 1998-06-01 10:18:31 -0400
4538
4539  addition to localtime.c by Guy Harris
4540
4541
4542Release 1998e - 1998-05-28 09:56:26 -0400
4543
4544  The Makefile is changed to produce zoneinfo-posix rather than
4545  zoneinfo/posix, and to produce zoneinfo-leaps rather than
4546  zoneinfo/right.
4547
4548  data changes by Paul Eggert
4549
4550  changes from Guy Harris to provide asctime_r and ctime_r
4551
4552  A usno1998 file (substantially identical to usno1997) has been added.
4553
4554
4555Release 1998d - 1998-05-14 11:58:34 -0400
4556
4557  changes to comments (in particular, elimination of references to CIA maps).
4558  "Arts.htm", "WWW.htm", "asia", and "australasia" are the only places
4559  where changes occur.
4560
4561
4562Release 1998c - 1998-02-28 12:32:26 -0500
4563
4564  changes by Paul Eggert (save the "French correction," on which I'll
4565  wait for the dust to settle)
4566
4567  symlink changes
4568
4569  changes and additions to Arts.htm
4570
4571
4572Release 1998b - 1998-01-17 14:31:51 -0500
4573
4574  URL cleanups and additions
4575
4576
4577Release 1998a - 1998-01-13 12:37:35 -0500
4578
4579  changes by Paul Eggert
4580
4581
4582Release code1997i-data1997k - 1997-12-29 09:53:41 -0500
4583
4584  changes by Paul Eggert, with minor modifications from Arthur David
4585  Olson to make the files more browser friendly
4586
4587
4588Release code1997h-data1997j - 1997-12-18 17:47:35 -0500
4589
4590  minor changes to put "TZif" at the start of each timezone information file
4591
4592  a rule has also been added to the Makefile so you can
4593	make zones
4594  to just recompile the zone information files (rather than doing a
4595  full "make install" with its other effects).
4596
4597
4598Release data1997i - 1997-10-07 08:45:38 -0400
4599
4600  changes to Africa by Paul Eggert
4601
4602
4603Release code1997g-data1997h - 1997-09-04 16:56:54 -0400
4604
4605  corrections for Uruguay (and other locations)
4606
4607  Arthur David Olson's simple-minded fix allowing mktime to both
4608  correctly handle leap seconds and correctly handle tm_sec values
4609  upon which arithmetic has been performed.
4610
4611
4612Release code1997f-data1997g - 1997-07-19 13:15:02 -0400
4613
4614  Paul Eggert's updates
4615
4616  a small change to a function prototype;
4617
4618  "Music" has been renamed "Arts.htm", HTMLified, and augmented to
4619  include information on Around the World in Eighty Days.
4620
4621
4622Release code1997e-data1997f - 1997-05-03 18:52:34 -0400
4623
4624  fixes to zic's error handling
4625
4626  changes inspired by the item circulated on Slovenia
4627
4628  The description of Web resources has been HTMLified for browsing
4629  convenience.
4630
4631  A new piece of tz-related music has been added to the "Music" file.
4632
4633
4634Release code1997d-data1997e - 1997-03-29 12:48:52 -0500
4635
4636  Paul Eggert's latest suggestions
4637
4638
4639Release code1997c-data1997d - 1997-03-07 20:37:54 -0500
4640
4641  changes to "zic.c" to correct performance of the "-s" option
4642
4643  a new file "usno1997"
4644
4645
4646Release data1997c - 1997-03-04 09:58:18 -0500
4647
4648  changes in Israel
4649
4650
4651Release 1997b - 1997-02-27 18:34:19 -0500
4652
4653  The data file incorporates the 1997 leap second.
4654
4655  The code file incorporates Arthur David Olson's take on the
4656  zic/multiprocessor/directory-creation situation.
4657
4658
4659Release 1997a - 1997-01-21 09:11:10 -0500
4660
4661  Paul Eggert's Antarctica (and other changes)
4662
4663  Arthur David Olson finessed the "getopt" issue by checking against
4664  both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1
4665  is returned while SunOS 5.5's manual says EOF is returned).
4666
4667
4668Release code1996o-data1996n - 1996-12-27 21:42:05 -0500
4669
4670  Paul Eggert's latest changes
4671
4672
4673Release code1996n - 1996-12-16 09:42:02 -0500
4674
4675  link snapping fix from Bruce Evans (via Garrett Wollman)
4676
4677
4678Release data1996m - 1996-11-24 02:37:34 -0000
4679  [tzdata1996m.tar.gz is missing!]
4680
4681  Paul Eggert's batch of changes
4682
4683
4684Release code1996m-data1996l - 1996-11-05 14:00:12 -0500
4685
4686  No functional changes here; the files have simply been changed to
4687  make more use of ISO style dates in comments. The names of the above
4688  files now include the year in full.
4689
4690
4691Release code96l - 1996-09-08 17:12:20 -0400
4692
4693  tzcode96k was missing a couple of pieces.
4694
4695
4696Release 96k - 1996-09-08 16:06:22 -0400
4697
4698  the latest round of changes from Paul Eggert
4699
4700  the recent Year 2000 material
4701
4702
4703Release code96j - 1996-07-30 13:18:53 -0400
4704
4705  Set sp->typecnt as suggested by Timothy Patrick Murphy.
4706
4707
4708Release code96i - 1996-07-27 20:11:35 -0400
4709
4710  Paul's suggested patch for strftime %V week numbers
4711
4712
4713Release data96i - 1996-07-01 18:13:04 -0400
4714
4715  "northamerica" and "europe" changes by Paul Eggert
4716
4717
4718Release code96h - 1996-06-05 08:02:21 -0400
4719
4720  fix for handling transitions specified in Universal Time
4721
4722  Some "public domain" notices have also been added.
4723
4724
4725Release code96g - 1996-05-16 14:00:26 -0400
4726
4727  fix for the simultaneous-DST-and-zone-change challenge
4728
4729
4730Release data96h - 1996-05-09 17:40:51 -0400
4731
4732  changes by Paul Eggert
4733
4734
4735Release code96f-data96g - 1996-05-03 03:09:59 -0000
4736  [tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!]
4737
4738  The changes get us some of the way to fixing the problems noted in Paul
4739  Eggert's letter yesterday (in addition to a few others).  The approach
4740  has been to make zic a bit smarter about figuring out what time zone
4741  abbreviations apply just after the time specified in the "UNTIL" part
4742  of a zone line.  Putting the smarts in zic means avoiding having
4743  transition times show up in both "Zone" lines and "Rule" lines, which
4744  in turn avoids multiple transition time entries in time zone files.
4745  (This also makes the zic input files such as "europe" a bit shorter and
4746  should ease maintenance.)
4747
4748
4749Release data96f - 1996-04-19 19:20:03 -0000
4750  [tzdata96f.tar.gz is missing!]
4751
4752  The only changes are to the "northamerica" file; the time zone
4753  abbreviation for Denver is corrected to MST (and MDT), and the
4754  comments for Mexico have been updated.
4755
4756
4757Release data96e - 1996-03-19 17:37:26 -0500
4758
4759  Proposals by Paul Eggert, in particular the Portugal change that
4760  comes into play at the end of this month.
4761
4762
4763Release data96d - 1996-03-18 20:49:39 -0500
4764
4765  [not summarized]
4766
4767
4768Release code96e - 1996-02-29 15:43:27 -0000
4769  [tzcode96e.tar.gz is missing!]
4770
4771  internationalization changes and the fix to the documentation for strftime
4772
4773
4774Release code96d-data96c - 1996-02-12 11:05:27 -0500
4775
4776  The "code" file simply updates Bob Kridle's electronic address.
4777
4778  The "data" file updates rules for Mexico.
4779
4780
4781Release data96b - 1996-01-27 15:44:42 -0500
4782
4783  Kiribati change
4784
4785
4786Release code96c - 1996-01-16 16:58:15 -0500
4787
4788  leap-year streamlining and binary-search changes
4789
4790  fix to newctime.3
4791
4792
4793Release code96b - 1996-01-10 20:42:39 -0500
4794
4795  fixes and enhancements from Paul Eggert, including code that
4796  emulates the behavior of recent versions of the SunOS "date"
4797  command.
4798
4799
4800Release 96a - 1996-01-06 09:08:24 -0500
4801
4802  Israel updates
4803
4804  fixes to strftime.c for correct ISO 8601 week number generation,
4805  plus support for two new formats ('G' and 'g') to give ISO 8601 year
4806  numbers (which are not necessarily the same as calendar year numbers)
4807
4808
4809Release code95i-data95m - 1995-12-21 12:46:47 -0500
4810
4811  The latest revisions from Paul Eggert are included, the usno1995
4812  file has been updated, and a new file ("WWW") covering useful URLs
4813  has been added.
4814
4815
4816Release code95h-data95l - 1995-12-19 18:10:12 -0500
4817
4818  A simplification of a macro definition, a change to data for Sudan,
4819  and (for last minute shoppers) notes in the "Music" file on the CD
4820  "Old Man Time".
4821
4822
4823Release code95g-data95k - 1995-10-30 10:32:47 -0500
4824
4825  (slightly reformatted) 8-bit-clean proposed patch
4826
4827  minor patch: US/Eastern -> America/New_York
4828
4829  snapshot of the USNO's latest data ("usno1995")
4830
4831  some other minor cleanups
4832
4833
4834Release code95f-data95j - 1995-10-28 21:01:34 -0000
4835  [tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!]
4836
4837  European cleanups
4838
4839  support for 64-bit time_t's
4840
4841  optimization in localtime.c
4842
4843
4844Release code95e - 1995-10-13 13:23:57 -0400
4845
4846  the mktime change to scan from future to past when trying to find time zone
4847  offsets
4848
4849
4850Release data95i - 1995-09-26 10:43:26 -0400
4851
4852  For Canada/Central, guess that the Sun customer's "one week too
4853  early" was just a approximation, and the true error is one month
4854  too early.  This is consistent with the rest of Canada.
4855
4856
4857Release data95h - 1995-09-21 11:26:48 -0400
4858
4859  latest changes from Paul Eggert
4860
4861
4862Release code95d - 1995-09-14 11:14:45 -0400
4863
4864  the addition of a "Music" file, which documents four recorded
4865  versions of the tune "Save That Time".
4866
4867
4868Release data95g - 1995-09-01 17:21:36 -0400
4869
4870  "yearistype" correction
4871
4872
4873Release data95f - 1995-08-28 20:46:56 -0400
4874
4875  Paul Eggert's change to the australasia file
4876
4877
4878Release data95e - 1995-07-08 18:02:34 -0400
4879
4880  The only change is a leap second at the end of this year.
4881  Thanks to Bradley White for forwarding news on the leap second.
4882
4883
4884Release data95d - 1995-07-03 13:26:22 -0400
4885
4886  Paul Eggert's changes
4887
4888
4889Release data95c - 1995-07-02 19:19:28 -0400
4890
4891  changes to "asia", "backward", "europe", and "southamerica"
4892  (read: northamericacentrics need not apply)
4893
4894
4895Release code95c - 1995-03-13 14:00:46 -0500
4896
4897  one-line fix for sign extension problems in detzcode
4898
4899
4900Release 95b - 1995-03-04 11:22:38 -0500
4901
4902  Minor changes in both:
4903
4904  The "code" file contains a workaround for the lack of "unistd.h" in
4905  Microsoft C++ version 7.
4906
4907  The "data" file contains a fixed "Link" for America/Shiprock.
4908
4909
4910Release 94h - 1994-12-10 12:51:14 -0500
4911
4912  The files:
4913
4914  *	incorporate the changes to "zdump" and "date" to make changes to
4915	the "TZ" environment variable permanent;
4916
4917  *	incorporate the table changes by Paul Eggert;
4918
4919  *	include (and document) support for universal time specifications in
4920	data files - but do not (yet) include use of this feature in the
4921	data files.
4922
4923  Think of this as "TZ Classic" - the software has been set up not to break if
4924  universal time shows up in its input, and data entries have been
4925  left as is so as not to break existing implementations.
4926
4927
4928Release data94f - 1994-08-20 12:56:09 -0400
4929
4930  (with thanks!) the latest data updates from Paul Eggert
4931
4932
4933Release data94e - 1994-06-04 13:13:53 -0400
4934
4935  [not summarized]
4936
4937
4938Release code94g - 1994-05-05 12:14:07 -0400
4939
4940  fix missing "optind.c" and a reference to it in the Makefile
4941
4942
4943Release code94f - 1994-05-05 13:00:33 -0000
4944  [tzcode94f.tar.gz is missing!]
4945
4946  changes to avoid overflow in difftime, as well as changes to cope
4947  with the 52/53 challenge in strftime
4948
4949
4950Release code94e - 1994-03-30 23:32:59 -0500
4951
4952  change for the benefit of PCTS
4953
4954
4955Release 94d - 1994-02-24 15:42:25 -0500
4956
4957  Avoid clashes with POSIX semantics for zones such as GMT+4.
4958
4959  Some other very minor housekeeping is also present.
4960
4961
4962Release code94c - 1994-02-10 08:52:40 -0500
4963
4964  Fix bug where mkdirs was broken unless you compile with
4965  -fwritable-strings (which is generally losing to do).
4966
4967
4968Release 94b - 1994-02-07 10:04:33 -0500
4969
4970  work by Paul Eggert who notes:
4971
4972  I found another book of time zone histories by E W Whitman; it's not
4973  as extensive as Shanks but has a few goodies of its own.  I used it
4974  to update the tables.  I also fixed some more as a result of
4975  correspondence with Adam David and Peter Ilieve, and move some stray
4976  links from 'europe' to 'backward'.  I corrected some scanning errors
4977  in usno1989.
4978
4979  As far as the code goes, I fixed zic to allow years in the range
4980  INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900.
4981  And I cleaned up the zic documentation a little bit.
4982
4983
4984Release data94a - 1994-02-03 08:58:54 -0500
4985
4986  It simply incorporates the recently announced leap second into the
4987  "leapseconds" file.
4988
4989
4990Release 93g - 1993-11-22 17:28:27 -0500
4991
4992  Paul Eggert has provided a good deal of historic information (based
4993  on Shanks), and there are some code changes to deal with the buglets
4994  that crawled out in dealing with the new information.
4995
4996
4997Release 93f - 1993-10-15 12:27:46 -0400
4998
4999  Paul Eggert's changes
5000
5001
5002Release 93e - 1993-09-05 21:21:44 -0400
5003
5004  This has updated data for Israel, England, and Kwajalein.  There's
5005  also an update to "zdump" to cope with Kwajalein's 24-hour jump.
5006  Thanks to Paul Eggert and Peter Ilieve for the changes.
5007
5008
5009Release 93d - 1993-06-17 23:34:17 -0400
5010
5011  new fix and new data on Israel
5012
5013
5014Release 93c - 1993-06-06 19:31:55 -0400
5015
5016  [not summarized]
5017
5018
5019Release 93b - 1993-02-02 14:53:58 -0500
5020
5021  updated "leapseconds" file
5022
5023
5024Release 93 - 1993-01-08 07:01:06 -0500
5025
5026  At kre's suggestion, the package has been split in two - a code piece
5027  (which also includes documentation) that's only of use to folks who
5028  want to recompile things and a data piece useful to anyone who can
5029  run "zic".
5030
5031  The new version has a few changes to the data files, a few
5032  portability changes, and an off-by-one fix (with thanks to
5033  Tom Karzes at deshaw.com for providing a description and a
5034  solution).
5035
5036
5037Release 92c - 1992-11-21 17:35:36 -0000
5038  [tz92c.tar.Z is missing!]
5039
5040  The fallout from the latest round of DST transitions.
5041
5042  There are changes for Portugal, Saskatchewan, and "Pacific-New";
5043  there's also a change to "zic.c" that makes it portable to more systems.
5044
5045
5046Release 92 - 1992-04-25 18:17:03 -0000
5047  [tz92.tar.Z is missing!]
5048
5049  By popular demand (well, at any rate, following a request by kre at munnari)
5050
5051
5052The 1989 update of the time zone package featured:
5053
5054  *	POSIXization (including interpretation of POSIX-style TZ environment
5055	variables, provided by Guy Harris),
5056  *	ANSIfication (including versions of "mktime" and "difftime"),
5057  *	SVIDulation (an "altzone" variable)
5058  *	MACHination (the "gtime" function)
5059  *	corrections to some time zone data (including corrections to the rules
5060	for Great Britain and New Zealand)
5061  *	reference data from the United States Naval Observatory for folks who
5062	want to do additional time zones
5063  *	and the 1989 data for Saudi Arabia.
5064
5065  (Since this code will be treated as "part of the implementation" in some
5066  places and as "part of the application" in others, there's no good way to
5067  name functions, such as timegm, that are not part of the proposed ANSI C
5068  standard; such functions have kept their old, underscore-free names in this
5069  update.)
5070
5071  And the "dysize" function has disappeared; it was present to allow
5072  compilation of the "date" command on old BSD systems, and a version of "date"
5073  is now provided in the package.  The "date" command is not created when you
5074  "make all" since it may lack options provided by the version distributed with
5075  your operating system, or may not interact with the system in the same way
5076  the native version does.
5077
5078  Since POSIX frowns on correct leap second handling, the default behavior of
5079  the "zic" command (in the absence of a "-L" option) has been changed to omit
5080  leap second information from its output files.
5081
5082
5083-----
5084Notes
5085
5086This file contains copies of the part of each release announcement
5087that talks about the changes in that release.  The text has been
5088adapted and reformatted for the purposes of this file.
5089
5090Traditionally a release R consists of a pair of tarball files,
5091tzcodeR.tar.gz and tzdataR.tar.gz.  However, some releases (e.g.,
5092code2010a, data2012c) consist of just one or the other tarball, and a
5093few (e.g., code2012c-data2012d) have tarballs with mixed version
5094numbers.  Recent releases also come in an experimental format
5095consisting of a single tarball tzdb-R.tar.lz with extra data.
5096
5097Release timestamps are taken from the release's commit (for newer,
5098Git-based releases), from the newest file in the tarball (for older
5099releases, where this info is available) or from the email announcing
5100the release (if all else fails; these are marked with a time zone
5101abbreviation of -0000 and an "is missing!" comment).
5102
5103Earlier versions of the code and data were not announced on the tz
5104list and are not summarized here.
5105
5106This file is in the public domain.
5107
5108Local Variables:
5109coding: utf-8
5110End:
5111