Lines Matching +full:data +full:- +full:only

2 .\" 1996-06-05 by Arthur David Olson.
15 Each file is a sequence of 8-bit bytes.
17 more bytes in network order (bigendian, or high-order byte first),
20 and a boolean is represented by a one-byte binary integer that is
22 The format begins with a 44-byte header containing the following fields:
24 .Bl -bullet
26 The magic four-byte ASCII sequence
39 Six four-byte integer values, in the following order:
41 .Bl -tag -compat -width tzh_ttisstdcnt
48 The number of leap seconds for which data entries are stored in the file.
50 The number of transition times for which data entries are stored
53 The number of local time types for which data entries are stored
63 .Bl -tag -compat -width tzh_timecnt
65 four-byte signed integer values sorted in ascending order.
71 one-byte unsigned integer values;
74 starting with the same-indexed transition time
76 (The last time type is present only for consistency checking with the
83 .Bd -literal -offset indent
91 Each structure is written as a four-byte signed integer value for
93 in network byte order, followed by a one-byte boolean for
95 and a one-byte value for
110 entries in the file; if the designated string is "\*-00", the
115 value is never equal to \-2**31, to let 32-bit clients negate it without
119 is in the range [\-89999, 93599] (i.e., more than \-25 hours and less
121 already support the POSIX-required range [\-24:59:59, 25:59:59].
124 which are null-terminated byte strings, each indexed by the
130 pairs of four-byte values, written in network byte order;
145 and is a positive leap second if and only if its correction is positive;
148 or \-1 for a negative leap second.
149 If the leap second table is empty, the leap-second correction is zero
152 the leap-second correction is zero if the first pair's correction is 1 or \-1,
153 and is unspecified otherwise (which can happen only in files
156 standard/wall indicators, each stored as a one-byte boolean;
160 UT/local indicators, each stored as a one-byte boolean;
171 For example, when TZ="EET\*-2EEST" and there is no TZif file "EET\*-2EEST",
173 well-known name "posixrules" that is present only for this purpose and
176 the default rules are installation-dependent, and no implementation
180 TZ="EET\*-2EEST,M3.5.0/3,M10.5.0/4" if POSIX conformance is required
194 For version-2-format timezone files,
195 the above header and data are followed by a second header and data,
199 After the second header and data comes a newline-enclosed string
207 type after the last transition time if present in the eight-byte data;
211 type must specify a daylight-saving time abbreviated
218 For version-3-format timezone files, a TZ string (see
220 may use the following POSIX.1-2024 extensions to POSIX.1-2017:
221 First, as in TZ="<\*-02>2<\*-01>,M3.5.0/\*-1,M10.5.0/0",
223 \-167 through 167 instead of being limited to unsigned values
229 For version-4-format TZif files,
231 +1 nor \-1, to represent truncation of the TZif file at the start.
237 the added leap seconds will change how post-expiration timestamps are treated.
239 Future changes to the format may append more data.
244 Readers that understand only Version 1 must ignore
245 any data that extends beyond the calculated end of the version
246 1 data block.
249 the lowest version number needed by a file's data.
251 only if its leap second table either expires or is truncated at the start.
253 should generate a version 3 file only if
258 header and data block should be a contiguous sub-sequence
259 of the time changes defined by the version 2+ header and data
263 contiguous sub-sequence.
268 in the version 1 data block to save space.
272 post-expiration timestamps, or process them as if the expiration
278 .Dq "\*-" ,
285 should ignore the version 1 header and data block except for
289 headers and data blocks and check that they all fit within
304 .Bl -bullet
323 new-version data useful even for older-version readers.
329 .Bl -bullet
331 Some readers examine only version 1 data.
333 data as possible.
334 However, a reader should ignore version 1 data, and should use
335 version 2+ data even if the reader's native timestamps have only
340 they cannot parse the POSIX.1-2024 extensions to POSIX.1-2017
343 than necessary, so that only far-future timestamps are
351 (\-04).
355 for a time zone with a never-used standard time (XXX, \-03)
356 and negative daylight saving time (EDT, \-04) all year.
362 Atlantic Standard Time (\-04).
373 Some stripped-down readers ignore everything but the footer,
381 .Dq <+01>\*-1 ,
382 which should be used only for timestamps after the last
388 As a partial workaround, a writer can output a dummy (no-op)
392 transition that has a timestamp not less than \-2**31.
393 Readers that support only 32-bit timestamps are likely to be
395 64-bit transitions only some of which are representable in 32
398 transition at timestamp \-2**31.
401 the minimum possible signed 64-bit value.
402 Timestamps less than \-2**59 are not recommended.
413 for time zone abbreviations containing only alphabetic
417 non-ASCII characters.
423 .Dq "\*-",
429 daylight-saving time UT offsets that are less than the UT
433 .Dq "IST\*-1GMT0,M10.5.0,M3.5.0/1",
436 As a partial workaround, a writer can output data for the
447 a positive leap second 78796801 (1972-06-30 23:59:60 UTC), some readers will
458 .Bl -bullet
462 in mind if they need to deal with pre-1970 data.
470 .Dq "\*-08"
473 .Dq "\*-" ,
477 traditional range of \-12 through +12 hours, and so do not
481 Some readers mishandle UT offsets in the range [\-3599, \-1]
482 seconds from UT, because they integer-divide the offset by