xref: /freebsd/contrib/tzdata/northamerica (revision 3d265fce43746c293ae826e9603adbfe09f93cf6)
1# tzdb data for North and Central America and environs
2
3# This file is in the public domain, so clarified as of
4# 2009-05-17 by Arthur David Olson.
5
6# also includes Central America and the Caribbean
7
8# This file is by no means authoritative; if you think you know better,
9# go ahead and edit the file (and please send any changes to
10# tz@iana.org for general use in the future).  For more, please see
11# the file CONTRIBUTING in the tz distribution.
12
13# From Paul Eggert (1999-03-22):
14# A reliable and entertaining source about time zones is
15# Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997).
16
17###############################################################################
18
19# United States
20
21# From Paul Eggert (1999-03-31):
22# Howse writes (pp 121-125) that time zones were invented by
23# Professor Charles Ferdinand Dowd (1825-1904),
24# Principal of Temple Grove Ladies' Seminary (Saratoga Springs, NY).
25# His pamphlet "A System of National Time for Railroads" (1870)
26# was the result of his proposals at the Convention of Railroad Trunk Lines
27# in New York City (1869-10).  His 1870 proposal was based on Washington, DC,
28# but in 1872-05 he moved the proposed origin to Greenwich.
29
30# From Paul Eggert (2018-03-20):
31# Dowd's proposal left many details unresolved, such as where to draw
32# lines between time zones.  The key individual who made time zones
33# work in the US was William Frederick Allen - railway engineer,
34# managing editor of the Travelers' Guide, and secretary of the
35# General Time Convention, a railway standardization group.  Allen
36# spent months in dialogs with scientific and railway leaders,
37# developed a workable plan to institute time zones, and presented it
38# to the General Time Convention on 1883-04-11, saying that his plan
39# meant "local time would be practically abolished" - a plus for
40# railway scheduling.  By the next convention on 1883-10-11 nearly all
41# railroads had agreed and it took effect on 1883-11-18.  That Sunday
42# was called the "day of two noons", as some locations observed noon
43# twice.  Allen witnessed the transition in New York City, writing:
44#
45#   I heard the bells of St. Paul's strike on the old time.  Four
46#   minutes later, obedient to the electrical signal from the Naval
47#   Observatory ... the time-ball made its rapid descent, the chimes
48#   of old Trinity rang twelve measured strokes, and local time was
49#   abandoned, probably forever.
50#
51# Most of the US soon followed suit.  See:
52# Bartky IR. The adoption of standard time. Technol Cult 1989 Jan;30(1):25-56.
53# https://dx.doi.org/10.2307/3105430
54
55# From Paul Eggert (2005-04-16):
56# That 1883 transition occurred at 12:00 new time, not at 12:00 old time.
57# See p 46 of David Prerau, Seize the daylight, Thunder's Mouth Press (2005).
58
59# From Paul Eggert (2006-03-22):
60# A good source for time zone historical data in the US is
61# Thomas G. Shanks, The American Atlas (5th edition),
62# San Diego: ACS Publications, Inc. (1991).
63# Make sure you have the errata sheet; the book is somewhat useless without it.
64# It is the source for most of the pre-1991 US entries below.
65
66# From Paul Eggert (2001-03-06):
67# Daylight Saving Time was first suggested as a joke by Benjamin Franklin
68# in his whimsical essay "An Economical Project for Diminishing the Cost
69# of Light" published in the Journal de Paris (1784-04-26).
70# Not everyone is happy with the results:
71#
72#	I don't really care how time is reckoned so long as there is some
73#	agreement about it, but I object to being told that I am saving
74#	daylight when my reason tells me that I am doing nothing of the kind.
75#	I even object to the implication that I am wasting something
76#	valuable if I stay in bed after the sun has risen.  As an admirer
77#	of moonlight I resent the bossy insistence of those who want to
78#	reduce my time for enjoying it.  At the back of the Daylight Saving
79#	scheme I detect the bony, blue-fingered hand of Puritanism, eager
80#	to push people into bed earlier, and get them up earlier, to make
81#	them healthy, wealthy and wise in spite of themselves.
82#
83#	 -- Robertson Davies, The diary of Samuel Marchbanks,
84#	   Clarke, Irwin (1947), XIX, Sunday
85#
86# For more about the first ten years of DST in the United States, see
87# Robert Garland, Ten years of daylight saving from the Pittsburgh standpoint
88# (Carnegie Library of Pittsburgh, 1927).
89# https://web.archive.org/web/20160517155308/http://www.clpgh.org/exhibit/dst.html
90#
91# Shanks says that DST was called "War Time" in the US in 1918 and 1919.
92# However, DST was imposed by the Standard Time Act of 1918, which
93# was the first nationwide legal time standard, and apparently
94# time was just called "Standard Time" or "Daylight Saving Time".
95
96# From Paul Eggert (2019-06-04):
97# Here is the legal basis for the US federal rules.
98# * Public Law 65-106 (1918-03-19) implemented standard and daylight saving
99#   time for the first time across the US, springing forward on March's last
100#   Sunday and falling back on October's last Sunday.
101#   https://www.loc.gov/law/help/statutes-at-large/65th-congress/session-2/c65s2ch24.pdf
102# * Public Law 66-40 (1919-08-20) repealed DST on October 1919's last Sunday.
103#   https://www.loc.gov/law/help/statutes-at-large/66th-congress/session-1/c66s1ch51.pdf
104# * Public Law 77-403 (1942-01-20) started wartime DST on 1942-02-09.
105#   https://www.loc.gov/law/help/statutes-at-large/77th-congress/session-2/c77s2ch7.pdf
106# * Public Law 79-187 (1945-09-25) ended wartime DST on 1945-09-30.
107#   https://www.loc.gov/law/help/statutes-at-large/79th-congress/session-1/c79s1ch388.pdf
108# * Public Law 89-387 (1966-04-13) reinstituted a national standard for DST,
109#   from April's last Sunday to October's last Sunday, effective 1967.
110#   https://www.govinfo.gov/content/pkg/STATUTE-80/pdf/STATUTE-80-Pg107.pdf
111# * Public Law 93-182 (1973-12-15) moved the 1974 spring-forward to 01-06.
112#   https://www.govinfo.gov/content/pkg/STATUTE-87/pdf/STATUTE-87-Pg707.pdf
113# * Public Law 93-434 (1974-10-05) moved the 1975 spring-forward to
114#   February's last Sunday.
115#   https://www.govinfo.gov/content/pkg/STATUTE-88/pdf/STATUTE-88-Pg1209.pdf
116# * Public Law 99-359 (1986-07-08) moved the spring-forward to April's first
117#   Sunday.
118#   https://www.govinfo.gov/content/pkg/STATUTE-100/pdf/STATUTE-100-Pg764.pdf
119# * Public Law 109-58 (2005-08-08), effective 2007, moved the spring-forward
120#   to March's second Sunday and the fall-back to November's first Sunday.
121#   https://www.govinfo.gov/content/pkg/PLAW-109publ58/pdf/PLAW-109publ58.pdf
122# All transitions are at 02:00 local time.
123
124# From Arthur David Olson:
125# Before the Uniform Time Act of 1966 took effect in 1967, observance of
126# Daylight Saving Time in the US was by local option, except during wartime.
127
128# From Arthur David Olson (2000-09-25):
129# Last night I heard part of a rebroadcast of a 1945 Arch Oboler radio drama.
130# In the introduction, Oboler spoke of "Eastern Peace Time."
131# An AltaVista search turned up:
132# https://web.archive.org/web/20000926032210/http://rowayton.org/rhs/hstaug45.html
133# "When the time is announced over the radio now, it is 'Eastern Peace
134# Time' instead of the old familiar 'Eastern War Time.'  Peace is wonderful."
135# (August 1945) by way of confirmation.
136#
137# From Paul Eggert (2017-09-23):
138# This was the V-J Day issue of the Clamdigger, a Rowayton, CT newsletter.
139
140# From Joseph Gallant citing
141# George H. Douglas, _The Early Days of Radio Broadcasting_ (1987):
142# At 7 P.M. (Eastern War Time) [on 1945-08-14], the networks were set
143# to switch to London for Attlee's address, but the American people
144# never got to hear his speech live. According to one press account,
145# CBS' Bob Trout was first to announce the word of Japan's surrender,
146# but a few seconds later, NBC, ABC and Mutual also flashed the word
147# of surrender, all of whom interrupting the bells of Big Ben in
148# London which were to precede Mr. Attlee's speech.
149
150# From Paul Eggert (2003-02-09): It was Robert St John, not Bob Trout.  From
151# Myrna Oliver's obituary of St John on page B16 of today's Los Angeles Times:
152#
153# ... a war-weary U.S. clung to radios, awaiting word of Japan's surrender.
154# Any announcement from Asia would reach St. John's New York newsroom on a
155# wire service teletype machine, which had prescribed signals for major news.
156# Associated Press, for example, would ring five bells before spewing out
157# typed copy of an important story, and 10 bells for news "of transcendental
158# importance."
159#
160# On Aug. 14, stalling while talking steadily into the NBC networks' open
161# microphone, St. John heard five bells and waited only to hear a sixth bell,
162# before announcing confidently: "Ladies and gentlemen, World War II is over.
163# The Japanese have agreed to our surrender terms."
164#
165# He had scored a 20-second scoop on other broadcasters.
166
167# From Arthur David Olson (2005-08-22):
168# Paul has been careful to use the "US" rules only in those locations
169# that are part of the United States; this reflects the real scope of
170# U.S. government action.  So even though the "US" rules have changed
171# in the latest release, other countries won't be affected.
172
173# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
174Rule	US	1918	1919	-	Mar	lastSun	2:00	1:00	D
175Rule	US	1918	1919	-	Oct	lastSun	2:00	0	S
176Rule	US	1942	only	-	Feb	9	2:00	1:00	W # War
177Rule	US	1945	only	-	Aug	14	23:00u	1:00	P # Peace
178Rule	US	1945	only	-	Sep	30	2:00	0	S
179Rule	US	1967	2006	-	Oct	lastSun	2:00	0	S
180Rule	US	1967	1973	-	Apr	lastSun	2:00	1:00	D
181Rule	US	1974	only	-	Jan	6	2:00	1:00	D
182Rule	US	1975	only	-	Feb	lastSun	2:00	1:00	D
183Rule	US	1976	1986	-	Apr	lastSun	2:00	1:00	D
184Rule	US	1987	2006	-	Apr	Sun>=1	2:00	1:00	D
185Rule	US	2007	max	-	Mar	Sun>=8	2:00	1:00	D
186Rule	US	2007	max	-	Nov	Sun>=1	2:00	0	S
187
188# From Arthur David Olson, 2005-12-19
189# We generate the files specified below to guard against old files with
190# obsolete information being left in the time zone binary directory.
191# We limit the list to names that have appeared in previous versions of
192# this time zone package.
193# We do these as separate Zones rather than as Links to avoid problems if
194# a particular place changes whether it observes DST.
195# We put these specifications here in the northamerica file both to
196# increase the chances that they'll actually get compiled and to
197# avoid the need to duplicate the US rules in another file.
198
199# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
200Zone	EST		 -5:00	-	EST
201Zone	MST		 -7:00	-	MST
202Zone	HST		-10:00	-	HST
203Zone	EST5EDT		 -5:00	US	E%sT
204Zone	CST6CDT		 -6:00	US	C%sT
205Zone	MST7MDT		 -7:00	US	M%sT
206Zone	PST8PDT		 -8:00	US	P%sT
207
208# From U. S. Naval Observatory (1989-01-19):
209# USA  EASTERN       5 H  BEHIND UTC    NEW YORK, WASHINGTON
210# USA  EASTERN       4 H  BEHIND UTC    APR 3 - OCT 30
211# USA  CENTRAL       6 H  BEHIND UTC    CHICAGO, HOUSTON
212# USA  CENTRAL       5 H  BEHIND UTC    APR 3 - OCT 30
213# USA  MOUNTAIN      7 H  BEHIND UTC    DENVER
214# USA  MOUNTAIN      6 H  BEHIND UTC    APR 3 - OCT 30
215# USA  PACIFIC       8 H  BEHIND UTC    L.A., SAN FRANCISCO
216# USA  PACIFIC       7 H  BEHIND UTC    APR 3 - OCT 30
217# USA  ALASKA STD    9 H  BEHIND UTC    MOST OF ALASKA     (AKST)
218# USA  ALASKA STD    8 H  BEHIND UTC    APR 3 - OCT 30 (AKDT)
219# USA  ALEUTIAN     10 H  BEHIND UTC    ISLANDS WEST OF 170W
220# USA    "           9 H  BEHIND UTC    APR 3 - OCT 30
221# USA  HAWAII       10 H  BEHIND UTC
222# USA  BERING       11 H  BEHIND UTC    SAMOA, MIDWAY
223
224# From Arthur David Olson (1989-01-21):
225# The above dates are for 1988.
226# Note the "AKST" and "AKDT" abbreviations, the claim that there's
227# no DST in Samoa, and the claim that there is DST in Alaska and the
228# Aleutians.
229
230# From Arthur David Olson (1988-02-13):
231# Legal standard time zone names, from United States Code (1982 Edition and
232# Supplement III), Title 15, Chapter 6, Section 260 and forward.  First, names
233# up to 1967-04-01 (when most provisions of the Uniform Time Act of 1966
234# took effect), as explained in sections 263 and 261:
235#	(none)
236#	United States standard eastern time
237#	United States standard mountain time
238#	United States standard central time
239#	United States standard Pacific time
240#	(none)
241#	United States standard Alaska time
242#	(none)
243# Next, names from 1967-04-01 until 1983-11-30 (the date for
244# public law 98-181):
245#	Atlantic standard time
246#	eastern standard time
247#	central standard time
248#	mountain standard time
249#	Pacific standard time
250#	Yukon standard time
251#	Alaska-Hawaii standard time
252#	Bering standard time
253# And after 1983-11-30:
254#	Atlantic standard time
255#	eastern standard time
256#	central standard time
257#	mountain standard time
258#	Pacific standard time
259#	Alaska standard time
260#	Hawaii-Aleutian standard time
261#	Samoa standard time
262# The law doesn't give abbreviations.
263#
264# From Paul Eggert (2016-12-19):
265# Here are URLs for the 1918 and 1966 legislation:
266# http://uscode.house.gov/statviewer.htm?volume=40&page=451
267# http://uscode.house.gov/statviewer.htm?volume=80&page=108
268# Although the 1918 names were officially "United States Standard
269# Eastern Time" and similarly for "Central", "Mountain", "Pacific",
270# and "Alaska", in practice "Standard" was placed just before "Time",
271# as codified in 1966.  In practice, Alaska time was abbreviated "AST"
272# before 1968.  Summarizing the 1967 name changes:
273#	1918 names			1967 names
274#  -08	Standard Pacific Time (PST)	Pacific standard time (PST)
275#  -09	(unofficial) Yukon (YST)	Yukon standard time (YST)
276#  -10	Standard Alaska Time (AST)	Alaska-Hawaii standard time (AHST)
277#  -11	(unofficial) Nome (NST)		Bering standard time (BST)
278#
279# From Paul Eggert (2000-01-08), following a heads-up from Rives McDow:
280# Public law 106-564 (2000-12-23) introduced ... "Chamorro Standard Time"
281# for time in Guam and the Northern Marianas.  See the file "australasia".
282#
283# From Paul Eggert (2015-04-17):
284# HST and HDT are standardized abbreviations for Hawaii-Aleutian
285# standard and daylight times.  See section 9.47 (p 234) of the
286# U.S. Government Printing Office Style Manual (2008)
287# https://www.gpo.gov/fdsys/pkg/GPO-STYLEMANUAL-2008/pdf/GPO-STYLEMANUAL-2008.pdf
288
289# From Arthur David Olson, 2005-08-09
290# The following was signed into law on 2005-08-08.
291#
292# H.R. 6, Energy Policy Act of 2005, SEC. 110. DAYLIGHT SAVINGS.
293#   (a) Amendment.--Section 3(a) of the Uniform Time Act of 1966 (15
294#   U.S.C. 260a(a)) is amended--
295#     (1) by striking "first Sunday of April" and inserting "second
296#     Sunday of March"; and
297#     (2) by striking "last Sunday of October" and inserting "first
298#     Sunday of November'.
299#   (b) Effective Date.--Subsection (a) shall take effect 1 year after the
300#   date of enactment of this Act or March 1, 2007, whichever is later.
301#   (c) Report to Congress.--Not later than 9 months after the effective
302#   date stated in subsection (b), the Secretary shall report to Congress
303#   on the impact of this section on energy consumption in the United
304#   States.
305#   (d) Right to Revert.--Congress retains the right to revert the
306#   Daylight Saving Time back to the 2005 time schedules once the
307#   Department study is complete.
308
309# US eastern time, represented by New York
310
311# Connecticut, Delaware, District of Columbia, most of Florida,
312# Georgia, southeast Indiana (Dearborn and Ohio counties), eastern Kentucky
313# (except America/Kentucky/Louisville below), Maine, Maryland, Massachusetts,
314# New Hampshire, New Jersey, New York, North Carolina, Ohio,
315# Pennsylvania, Rhode Island, South Carolina, eastern Tennessee,
316# Vermont, Virginia, West Virginia
317
318# From Dave Cantor (2004-11-02):
319# Early this summer I had the occasion to visit the Mount Washington
320# Observatory weather station atop (of course!) Mount Washington [, NH]....
321# One of the staff members said that the station was on Eastern Standard Time
322# and didn't change their clocks for Daylight Saving ... so that their
323# reports will always have times which are 5 hours behind UTC.
324
325# From Paul Eggert (2005-08-26):
326# According to today's Huntsville Times
327# http://www.al.com/news/huntsvilletimes/index.ssf?/base/news/1125047783228320.xml&coll=1
328# a few towns on Alabama's "eastern border with Georgia, such as Phenix City
329# in Russell County, Lanett in Chambers County and some towns in Lee County,
330# set their watches and clocks on Eastern time."  It quotes H.H. "Bubba"
331# Roberts, city administrator in Phenix City. as saying "We are in the Central
332# time zone, but we do go by the Eastern time zone because so many people work
333# in Columbus."
334#
335# From Paul Eggert (2017-02-22):
336# Four cities are involved.  The two not mentioned above are Smiths Station
337# and Valley.  Barbara Brooks, Valley's assistant treasurer, heard it started
338# because West Point Pepperell textile mills were in Alabama while the
339# corporate office was in Georgia, and residents voted to keep Eastern
340# time even after the mills closed.  See: Kazek K. Did you know which
341# Alabama towns are in a different time zone?  al.com 2017-02-06.
342# http://www.al.com/living/index.ssf/2017/02/do_you_know_which_alabama_town.html
343
344# From Paul Eggert (2014-09-06):
345# Monthly Notices of the Royal Astronomical Society 44, 4 (1884-02-08), 208
346# says that New York City Hall time was 3 minutes 58.4 seconds fast of
347# Eastern time (i.e., -4:56:01.6) just before the 1883 switch.  Round to the
348# nearest second.
349
350# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
351Rule	NYC	1920	only	-	Mar	lastSun	2:00	1:00	D
352Rule	NYC	1920	only	-	Oct	lastSun	2:00	0	S
353Rule	NYC	1921	1966	-	Apr	lastSun	2:00	1:00	D
354Rule	NYC	1921	1954	-	Sep	lastSun	2:00	0	S
355Rule	NYC	1955	1966	-	Oct	lastSun	2:00	0	S
356# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
357Zone America/New_York	-4:56:02 -	LMT	1883 Nov 18 12:03:58
358			-5:00	US	E%sT	1920
359			-5:00	NYC	E%sT	1942
360			-5:00	US	E%sT	1946
361			-5:00	NYC	E%sT	1967
362			-5:00	US	E%sT
363
364# US central time, represented by Chicago
365
366# Alabama, Arkansas, Florida panhandle (Bay, Calhoun, Escambia,
367# Gulf, Holmes, Jackson, Okaloosa, Santa Rosa, Walton, and
368# Washington counties), Illinois, western Indiana
369# (Gibson, Jasper, Lake, LaPorte, Newton, Porter, Posey, Spencer,
370# Vanderburgh, and Warrick counties), Iowa, most of Kansas, western
371# Kentucky, Louisiana, Minnesota, Mississippi, Missouri, eastern
372# Nebraska, eastern North Dakota, Oklahoma, eastern South Dakota,
373# western Tennessee, most of Texas, Wisconsin
374
375# From Paul Eggert (2018-01-07):
376# In 1869 the Chicago Astronomical Society contracted with the city to keep
377# time.  Though delayed by the Great Fire, by 1880 a wire ran from the
378# Dearborn Observatory (on the University of Chicago campus) to City Hall,
379# which then sent signals to police and fire stations.  However, railroads got
380# their time signals from the Allegheny Observatory, the Madison Observatory,
381# the Ann Arbor Observatory, etc., so their clocks did not agree with each
382# other or with the city's official time.  The confusion took some years to
383# clear up.  See:
384# Moser M. How Chicago gave America its time zones. Chicago. 2018-01-04.
385# http://www.chicagomag.com/city-life/January-2018/How-Chicago-Gave-America-Its-Time-Zones/
386
387# From Larry M. Smith (2006-04-26) re Wisconsin:
388# https://docs.legis.wisconsin.gov/statutes/statutes/175.pdf
389# is currently enforced at the 01:00 time of change.  Because the local
390# "bar time" in the state corresponds to 02:00, a number of citations
391# are issued for the "sale of class 'B' alcohol after prohibited
392# hours" within the deviated hour of this change every year....
393#
394# From Douglas R. Bomberg (2007-03-12):
395# Wisconsin has enacted (nearly eleventh-hour) legislation to get WI
396# Statue 175 closer in synch with the US Congress' intent....
397# https://docs.legis.wisconsin.gov/2007/related/acts/3
398
399# From an email administrator of the City of Fort Pierre, SD (2015-12-21):
400# Fort Pierre is technically located in the Mountain time zone as is
401# the rest of Stanley County.  Most of Stanley County and Fort Pierre
402# uses the Central time zone due to doing most of their business in
403# Pierre so it simplifies schedules.  I have lived in Stanley County
404# all my life and it has been that way since I can remember.  (43 years!)
405#
406# From Paul Eggert (2015-12-25):
407# Assume this practice predates 1970, so Fort Pierre can use America/Chicago.
408
409# From Paul Eggert (2015-04-06):
410# In 1950s Nashville a public clock had dueling faces, one for conservatives
411# and the other for liberals; the two sides didn't agree about the time of day.
412# I haven't found a photo of this clock, nor have I tracked down the TIME
413# magazine report cited below, but here's the story as told by the late
414# American journalist John Seigenthaler, who was there:
415#
416# "The two [newspaper] owners held strongly contrasting political and
417# ideological views.  Evans was a New South liberal, Stahlman an Old South
418# conservative, and their two papers frequently clashed editorially, often on
419# the same day....  In the 1950s as the state legislature was grappling with
420# the question of whether to approve daylight saving time for the entire state,
421# TIME magazine reported:
422#
423# "'The Nashville Banner and The Nashville Tennessean rarely agree on anything
424# but the time of day - and last week they couldn't agree on that.'
425#
426# "It was all too true. The clock on the front of the building had two faces -
427# The Tennessean side of the building facing west, the other, east.  When it
428# was high noon Banner time, it was 11 a.m. Tennessean time."
429#
430# Seigenthaler J. For 100 years, Tennessean had it covered.
431# The Tennessean 2007-05-11, republished 2015-04-06.
432# https://www.tennessean.com/story/insider/extras/2015/04/06/archives-seigenthaler-for-100-years-the-tennessean-had-it-covered/25348545/
433
434# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
435Rule	Chicago	1920	only	-	Jun	13	2:00	1:00	D
436Rule	Chicago	1920	1921	-	Oct	lastSun	2:00	0	S
437Rule	Chicago	1921	only	-	Mar	lastSun	2:00	1:00	D
438Rule	Chicago	1922	1966	-	Apr	lastSun	2:00	1:00	D
439Rule	Chicago	1922	1954	-	Sep	lastSun	2:00	0	S
440Rule	Chicago	1955	1966	-	Oct	lastSun	2:00	0	S
441# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
442Zone America/Chicago	-5:50:36 -	LMT	1883 Nov 18 12:09:24
443			-6:00	US	C%sT	1920
444			-6:00	Chicago	C%sT	1936 Mar  1  2:00
445			-5:00	-	EST	1936 Nov 15  2:00
446			-6:00	Chicago	C%sT	1942
447			-6:00	US	C%sT	1946
448			-6:00	Chicago	C%sT	1967
449			-6:00	US	C%sT
450# Oliver County, ND switched from mountain to central time on 1992-10-25.
451Zone America/North_Dakota/Center -6:45:12 - LMT	1883 Nov 18 12:14:48
452			-7:00	US	M%sT	1992 Oct 25  2:00
453			-6:00	US	C%sT
454# Morton County, ND, switched from mountain to central time on
455# 2003-10-26, except for the area around Mandan which was already central time.
456# See <http://dmses.dot.gov/docimages/p63/135818.pdf>.
457# Officially this switch also included part of Sioux County, and
458# Jones, Mellette, and Todd Counties in South Dakota;
459# but in practice these other counties were already observing central time.
460# See <http://www.epa.gov/fedrgstr/EPA-IMPACT/2003/October/Day-28/i27056.htm>.
461Zone America/North_Dakota/New_Salem -6:45:39 - LMT	1883 Nov 18 12:14:21
462			-7:00	US	M%sT	2003 Oct 26  2:00
463			-6:00	US	C%sT
464
465# From Josh Findley (2011-01-21):
466# ...it appears that Mercer County, North Dakota, changed from the
467# mountain time zone to the central time zone at the last transition from
468# daylight-saving to standard time (on Nov. 7, 2010):
469# https://www.gpo.gov/fdsys/pkg/FR-2010-09-29/html/2010-24376.htm
470# http://www.bismarcktribune.com/news/local/article_1eb1b588-c758-11df-b472-001cc4c03286.html
471
472# From Andy Lipscomb (2011-01-24):
473# ...according to the Census Bureau, the largest city is Beulah (although
474# it's commonly referred to as Beulah-Hazen, with Hazen being the next
475# largest city in Mercer County).  Google Maps places Beulah's city hall
476# at 47° 15' 51" N, 101° 46' 40" W, which yields an offset of 6h47'07".
477
478Zone America/North_Dakota/Beulah -6:47:07 - LMT	1883 Nov 18 12:12:53
479			-7:00	US	M%sT	2010 Nov  7  2:00
480			-6:00	US	C%sT
481
482# US mountain time, represented by Denver
483#
484# Colorado, far western Kansas, Montana, western
485# Nebraska, Nevada border (Jackpot, Owyhee, and Mountain City),
486# New Mexico, southwestern North Dakota,
487# western South Dakota, far western Texas (El Paso County, Hudspeth County,
488# and Pine Springs and Nickel Creek in Culberson County), Utah, Wyoming
489#
490# From Paul Eggert (2018-10-25):
491# On 1921-03-04 federal law placed all of Texas into the central time zone.
492# However, El Paso ignored the law for decades and continued to observe
493# mountain time, on the grounds that that's what they had always done
494# and they weren't about to let the federal government tell them what to do.
495# Eventually the federal government gave in and changed the law on
496# 1970-04-10 to match what El Paso was actually doing.  Although
497# that's slightly after our 1970 cutoff, there is no need to create a
498# separate zone for El Paso since they were ignoring the law anyway.  See:
499# Long T. El Pasoans were time rebels, fought to stay in Mountain zone.
500# El Paso Times. 2018-10-24 06:40 -06.
501# https://www.elpasotimes.com/story/news/local/el-paso/2018/10/24/el-pasoans-were-time-rebels-fought-stay-mountain-zone/1744509002/
502#
503# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
504Rule	Denver	1920	1921	-	Mar	lastSun	2:00	1:00	D
505Rule	Denver	1920	only	-	Oct	lastSun	2:00	0	S
506Rule	Denver	1921	only	-	May	22	2:00	0	S
507Rule	Denver	1965	1966	-	Apr	lastSun	2:00	1:00	D
508Rule	Denver	1965	1966	-	Oct	lastSun	2:00	0	S
509# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
510Zone America/Denver	-6:59:56 -	LMT	1883 Nov 18 12:00:04
511			-7:00	US	M%sT	1920
512			-7:00	Denver	M%sT	1942
513			-7:00	US	M%sT	1946
514			-7:00	Denver	M%sT	1967
515			-7:00	US	M%sT
516
517# US Pacific time, represented by Los Angeles
518#
519# California, northern Idaho (Benewah, Bonner, Boundary, Clearwater,
520# Kootenai, Latah, Lewis, Nez Perce, and Shoshone counties, Idaho county
521# north of the Salmon River, and the towns of Burgdorf and Warren),
522# Nevada (except West Wendover), Oregon (except the northern ¾ of
523# Malheur county), and Washington
524
525# From Paul Eggert (2016-08-20):
526# In early February 1948, in response to California's electricity shortage,
527# PG&E changed power frequency from 60 to 59.5 Hz during daylight hours,
528# causing electric clocks to lose six minutes per day.  (This did not change
529# legal time, and is not part of the data here.)  See:
530# Ross SA. An energy crisis from the past: Northern California in 1948.
531# Working Paper No. 8, Institute of Governmental Studies, UC Berkeley,
532# 1973-11.  https://escholarship.org/uc/item/8x22k30c
533#
534# In another measure to save electricity, DST was instituted from 1948-03-14
535# at 02:01 to 1949-01-16 at 02:00, with the governor having the option to move
536# the fallback transition earlier.  See pages 3-4 of:
537# http://clerk.assembly.ca.gov/sites/clerk.assembly.ca.gov/files/archive/Statutes/1948/48Vol1_Chapters.pdf
538#
539# In response:
540#
541#   Governor Warren received a torrent of objecting mail, and it is not too much
542#   to speculate that the objections to Daylight Saving Time were one important
543#   factor in the defeat of the Dewey-Warren Presidential ticket in California.
544#     -- Ross, p 25
545#
546# On December 8 the governor exercised the option, setting the date to January 1
547# (LA Times 1948-12-09).  The transition time was 02:00 (LA Times 1949-01-01).
548#
549# Despite the controversy, in 1949 California voters approved Proposition 12,
550# which established DST from April's last Sunday at 01:00 until September's
551# last Sunday at 02:00. This was amended by 1962's Proposition 6, which changed
552# the fall-back date to October's last Sunday. See:
553# https://repository.uchastings.edu/cgi/viewcontent.cgi?article=1501&context=ca_ballot_props
554# https://repository.uchastings.edu/cgi/viewcontent.cgi?article=1636&context=ca_ballot_props
555#
556# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
557Rule	CA	1948	only	-	Mar	14	2:01	1:00	D
558Rule	CA	1949	only	-	Jan	 1	2:00	0	S
559Rule	CA	1950	1966	-	Apr	lastSun	1:00	1:00	D
560Rule	CA	1950	1961	-	Sep	lastSun	2:00	0	S
561Rule	CA	1962	1966	-	Oct	lastSun	2:00	0	S
562# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
563Zone America/Los_Angeles -7:52:58 -	LMT	1883 Nov 18 12:07:02
564			-8:00	US	P%sT	1946
565			-8:00	CA	P%sT	1967
566			-8:00	US	P%sT
567
568# Alaska
569# AK%sT is the modern abbreviation for -09 per USNO.
570#
571# From Paul Eggert (2017-06-15):
572# Howse writes that Alaska switched from the Julian to the Gregorian calendar,
573# and from east-of-GMT to west-of-GMT days, when the US bought it from Russia.
574# On Friday, 1867-10-18 (Gregorian), at precisely 15:30 local time, the
575# Russian forts and fleet at Sitka fired salutes to mark the ceremony of
576# formal transfer.  See the Sacramento Daily Union (1867-11-14), p 3, col 2.
577# https://cdnc.ucr.edu/cgi-bin/cdnc?a=d&d=SDU18671114.2.12.1
578# Sitka workers did not change their calendars until Sunday, 1867-10-20,
579# and so celebrated two Sundays that week.  See: Ahllund T (tr Hallamaa P).
580# From the memoirs of a Finnish workman. Alaska History. 2006 Fall;21(2):1-25.
581# http://alaskahistoricalsociety.org/wp-content/uploads/2016/12/Ahllund-2006-Memoirs-of-a-Finnish-Workman.pdf
582# Include only the time zone part of this transition, ignoring the switch
583# from Julian to Gregorian, since we can't represent the Julian calendar.
584#
585# As far as we know, of the locations mentioned below only Sitka was
586# permanently inhabited in 1867 by anyone using either calendar.
587# (Yakutat was colonized by the Russians in 1799, but the settlement was
588# destroyed in 1805 by a Yakutat-kon war party.)  Many of Alaska's inhabitants
589# were unaware of the US acquisition of Alaska, much less of any calendar or
590# time change.  However, the Russian-influenced part of Alaska did observe
591# Russian time, and it is more accurate to model this than to ignore it.
592# The database format requires an exact transition time; use the Russian
593# salute as a somewhat-arbitrary time for the formal transfer of control for
594# all of Alaska.  Sitka's UTC offset is -9:01:13; adjust its 15:30 to the
595# local times of other Alaskan locations so that they change simultaneously.
596
597# From Paul Eggert (2014-07-18):
598# One opinion of the early-1980s turmoil in Alaska over time zones and
599# daylight saving time appeared as graffiti on a Juneau airport wall:
600# "Welcome to Juneau.  Please turn your watch back to the 19th century."
601# See: Turner W. Alaska's four time zones now two. NY Times 1983-11-01.
602# http://www.nytimes.com/1983/11/01/us/alaska-s-four-time-zones-now-two.html
603#
604# Steve Ferguson (2011-01-31) referred to the following source:
605# Norris F. Keeping time in Alaska: national directives, local response.
606# Alaska History 2001;16(1-2).
607# http://alaskahistoricalsociety.org/discover-alaska/glimpses-of-the-past/keeping-time-in-alaska/
608
609# From Arthur David Olson (2011-02-01):
610# Here's database-relevant material from the 2001 "Alaska History" article:
611#
612# On September 20 [1979]...DOT...officials decreed that on April 27,
613# 1980, Juneau and other nearby communities would move to Yukon Time.
614# Sitka, Petersburg, Wrangell, and Ketchikan, however, would remain on
615# Pacific Time.
616#
617# ...on September 22, 1980, DOT Secretary Neil E. Goldschmidt rescinded the
618# Department's September 1979 decision. Juneau and other communities in
619# northern Southeast reverted to Pacific Time on October 26.
620#
621# On October 28 [1983]...the Metlakatla Indian Community Council voted
622# unanimously to keep the reservation on Pacific Time.
623#
624# According to DOT official Joanne Petrie, Indian reservations are not
625# bound to follow time zones imposed by neighboring jurisdictions.
626#
627# (The last is consistent with how the database now handles the Navajo
628# Nation.)
629
630# From Arthur David Olson (2011-02-09):
631# I just spoke by phone with a staff member at the Metlakatla Indian
632# Community office (using contact information available at
633# http://www.commerce.state.ak.us/dca/commdb/CIS.cfm?Comm_Boro_name=Metlakatla
634# It's shortly after 1:00 here on the east coast of the United States;
635# the staffer said it was shortly after 10:00 there. When I asked whether
636# that meant they were on Pacific time, they said no - they were on their
637# own time. I asked about daylight saving; they said it wasn't used. I
638# did not inquire about practices in the past.
639
640# From Arthur David Olson (2011-08-17):
641# For lack of better information, assume that Metlakatla's
642# abandonment of use of daylight saving resulted from the 1983 vote.
643
644# From Steffen Thorsen (2015-11-09):
645# It seems Metlakatla did go off PST on Sunday, November 1, changing
646# their time to AKST and are going to follow Alaska's DST, switching
647# between AKST and AKDT from now on....
648# https://www.krbd.org/2015/10/30/annette-island-times-they-are-a-changing/
649
650# From Ryan Stanley (2018-11-06):
651# The Metlakatla community in Alaska has decided not to change its
652# clock back an hour starting on November 4th, 2018 (day before yesterday).
653# They will be gmtoff=-28800 year-round.
654# https://www.facebook.com/141055983004923/photos/pb.141055983004923.-2207520000.1541465673./569081370202380/
655
656# From Paul Eggert (2018-12-16):
657# In a 2018-12-11 special election, Metlakatla voted to go back to
658# Alaska time (including daylight saving time) starting next year.
659# https://www.krbd.org/2018/12/12/metlakatla-to-follow-alaska-standard-time-allow-liquor-sales/
660#
661# From Ryan Stanley (2019-01-11):
662# The community will be changing back on the 20th of this month...
663# From Tim Parenti (2019-01-11):
664# Per an announcement on the Metlakatla community's official Facebook page, the
665# "fall back" will be on Sunday 2019-01-20 at 02:00:
666# https://www.facebook.com/141055983004923/photos/607150969728753/
667# So they won't be waiting for Alaska to join them on 2019-03-10, but will
668# rather change their clocks twice in seven weeks.
669
670# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
671Zone America/Juneau	 15:02:19 -	LMT	1867 Oct 19 15:33:32
672			 -8:57:41 -	LMT	1900 Aug 20 12:00
673			 -8:00	-	PST	1942
674			 -8:00	US	P%sT	1946
675			 -8:00	-	PST	1969
676			 -8:00	US	P%sT	1980 Apr 27  2:00
677			 -9:00	US	Y%sT	1980 Oct 26  2:00
678			 -8:00	US	P%sT	1983 Oct 30  2:00
679			 -9:00	US	Y%sT	1983 Nov 30
680			 -9:00	US	AK%sT
681Zone America/Sitka	 14:58:47 -	LMT	1867 Oct 19 15:30
682			 -9:01:13 -	LMT	1900 Aug 20 12:00
683			 -8:00	-	PST	1942
684			 -8:00	US	P%sT	1946
685			 -8:00	-	PST	1969
686			 -8:00	US	P%sT	1983 Oct 30  2:00
687			 -9:00	US	Y%sT	1983 Nov 30
688			 -9:00	US	AK%sT
689Zone America/Metlakatla	 15:13:42 -	LMT	1867 Oct 19 15:44:55
690			 -8:46:18 -	LMT	1900 Aug 20 12:00
691			 -8:00	-	PST	1942
692			 -8:00	US	P%sT	1946
693			 -8:00	-	PST	1969
694			 -8:00	US	P%sT	1983 Oct 30  2:00
695			 -8:00	-	PST	2015 Nov  1  2:00
696			 -9:00	US	AK%sT	2018 Nov  4  2:00
697			 -8:00	-	PST	2019 Jan 20  2:00
698			 -9:00	US	AK%sT
699Zone America/Yakutat	 14:41:05 -	LMT	1867 Oct 19 15:12:18
700			 -9:18:55 -	LMT	1900 Aug 20 12:00
701			 -9:00	-	YST	1942
702			 -9:00	US	Y%sT	1946
703			 -9:00	-	YST	1969
704			 -9:00	US	Y%sT	1983 Nov 30
705			 -9:00	US	AK%sT
706Zone America/Anchorage	 14:00:24 -	LMT	1867 Oct 19 14:31:37
707			 -9:59:36 -	LMT	1900 Aug 20 12:00
708			-10:00	-	AST	1942
709			-10:00	US	A%sT	1967 Apr
710			-10:00	-	AHST	1969
711			-10:00	US	AH%sT	1983 Oct 30  2:00
712			 -9:00	US	Y%sT	1983 Nov 30
713			 -9:00	US	AK%sT
714Zone America/Nome	 12:58:22 -	LMT	1867 Oct 19 13:29:35
715			-11:01:38 -	LMT	1900 Aug 20 12:00
716			-11:00	-	NST	1942
717			-11:00	US	N%sT	1946
718			-11:00	-	NST	1967 Apr
719			-11:00	-	BST	1969
720			-11:00	US	B%sT	1983 Oct 30  2:00
721			 -9:00	US	Y%sT	1983 Nov 30
722			 -9:00	US	AK%sT
723Zone America/Adak	 12:13:22 -	LMT	1867 Oct 19 12:44:35
724			-11:46:38 -	LMT	1900 Aug 20 12:00
725			-11:00	-	NST	1942
726			-11:00	US	N%sT	1946
727			-11:00	-	NST	1967 Apr
728			-11:00	-	BST	1969
729			-11:00	US	B%sT	1983 Oct 30  2:00
730			-10:00	US	AH%sT	1983 Nov 30
731			-10:00	US	H%sT
732# The following switches don't quite make our 1970 cutoff.
733#
734# Shanks writes that part of southwest Alaska (e.g. Aniak)
735# switched from -11:00 to -10:00 on 1968-09-22 at 02:00,
736# and another part (e.g. Akiak) made the same switch five weeks later.
737#
738# From David Flater (2004-11-09):
739# In e-mail, 2004-11-02, Ray Hudson, historian/liaison to the Unalaska
740# Historic Preservation Commission, provided this information, which
741# suggests that Unalaska deviated from statutory time from early 1967
742# possibly until 1983:
743#
744#  Minutes of the Unalaska City Council Meeting, January 10, 1967:
745#  "Except for St. Paul and Akutan, Unalaska is the only important
746#  location not on Alaska Standard Time.  The following resolution was
747#  made by William Robinson and seconded by Henry Swanson: Be it
748#  resolved that the City of Unalaska hereby goes to Alaska Standard
749#  Time as of midnight Friday, January 13, 1967 (1 A.M. Saturday,
750#  January 14, Alaska Standard Time.)  This resolution was passed with
751#  three votes for and one against."
752
753# Hawaii
754
755# From Arthur David Olson (2010-12-09):
756# "Hawaiian Time" by Robert C. Schmitt and Doak C. Cox appears on pages 207-225
757# of volume 26 of The Hawaiian Journal of History (1992). As of 2010-12-09,
758# the article is available at
759# https://evols.library.manoa.hawaii.edu/bitstream/10524/239/2/JL26215.pdf
760# and indicates that standard time was adopted effective noon, January
761# 13, 1896 (page 218), that in "1933, the Legislature decreed daylight
762# saving for the period between the last Sunday of each April and the
763# last Sunday of each September, but less than a month later repealed the
764# act," (page 220), that year-round daylight saving time was in effect
765# from 1942-02-09 to 1945-09-30 (page 221, with no time of day given for
766# when clocks changed) and that clocks were changed by 30 minutes
767# effective the second Sunday of June, 1947 (page 219, with no time of
768# day given for when clocks changed). A footnote for the 1933 changes
769# cites Session Laws of Hawaii 1933, "Act. 90 (approved 26 Apr. 1933)
770# and Act 163 (approved 21 May 1933)."
771
772# From Arthur David Olson (2011-01-19):
773# The following is from "Laws of the Territory of Hawaii Passed by the
774# Seventeenth Legislature: Regular Session 1933," available (as of
775# 2011-01-19) at American University's Pence Law Library. Page 85: "Act
776# 90...At 2 o'clock ante meridian of the last Sunday in April of each
777# year, the standard time of this Territory shall be advanced one
778# hour...This Act shall take effect upon its approval. Approved this 26th
779# day of April, A. D. 1933. LAWRENCE M JUDD, Governor of the Territory of
780# Hawaii." Page 172: "Act 163...Act 90 of the Session Laws of 1933 is
781# hereby repealed...This Act shall take effect upon its approval, upon
782# which date the standard time of this Territory shall be restored to
783# that existing immediately prior to the taking effect of said Act 90.
784# Approved this 21st day of May, A. D. 1933. LAWRENCE M. JUDD, Governor
785# of the Territory of Hawaii."
786#
787# Note that 1933-05-21 was a Sunday.
788# We're left to guess the time of day when Act 163 was approved; guess noon.
789
790# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
791Zone Pacific/Honolulu	-10:31:26 -	LMT	1896 Jan 13 12:00
792			-10:30	-	HST	1933 Apr 30  2:00
793			-10:30	1:00	HDT	1933 May 21 12:00
794			-10:30	US	H%sT	1947 Jun  8  2:00
795			-10:00	-	HST
796
797# Now we turn to US areas that have diverged from the consensus since 1970.
798
799# Arizona mostly uses MST.
800
801# From Paul Eggert (2002-10-20):
802#
803# The information in the rest of this paragraph is derived from the
804# Daylight Saving Time web page
805# <http://www.dlapr.lib.az.us/links/daylight.htm> (2002-01-23)
806# maintained by the Arizona State Library, Archives and Public Records.
807# Between 1944-01-01 and 1944-04-01 the State of Arizona used standard
808# time, but by federal law railroads, airlines, bus lines, military
809# personnel, and some engaged in interstate commerce continued to
810# observe war (i.e., daylight saving) time.  The 1944-03-17 Phoenix
811# Gazette says that was the date the law changed, and that 04-01 was
812# the date the state's clocks would change.  In 1945 the State of
813# Arizona used standard time all year, again with exceptions only as
814# mandated by federal law.  Arizona observed DST in 1967, but Arizona
815# Laws 1968, ch. 183 (effective 1968-03-21) repealed DST.
816#
817# Shanks says the 1944 experiment came to an end on 1944-03-17.
818# Go with the Arizona State Library instead.
819
820# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
821Zone America/Phoenix	-7:28:18 -	LMT	1883 Nov 18 11:31:42
822			-7:00	US	M%sT	1944 Jan  1  0:01
823			-7:00	-	MST	1944 Apr  1  0:01
824			-7:00	US	M%sT	1944 Oct  1  0:01
825			-7:00	-	MST	1967
826			-7:00	US	M%sT	1968 Mar 21
827			-7:00	-	MST
828# From Arthur David Olson (1988-02-13):
829# A writer from the Inter Tribal Council of Arizona, Inc.,
830# notes in private correspondence dated 1987-12-28 that "Presently, only the
831# Navajo Nation participates in the Daylight Saving Time policy, due to its
832# large size and location in three states."  (The "only" means that other
833# tribal nations don't use DST.)
834#
835# From Paul Eggert (2013-08-26):
836# See America/Denver for a zone appropriate for the Navajo Nation.
837
838# Southern Idaho (Ada, Adams, Bannock, Bear Lake, Bingham, Blaine,
839# Boise, Bonneville, Butte, Camas, Canyon, Caribou, Cassia, Clark,
840# Custer, Elmore, Franklin, Fremont, Gem, Gooding, Jefferson, Jerome,
841# Lemhi, Lincoln, Madison, Minidoka, Oneida, Owyhee, Payette, Power,
842# Teton, Twin Falls, Valley, Washington counties, and the southern
843# quarter of Idaho county) and eastern Oregon (most of Malheur County)
844# switched four weeks late in 1974.
845#
846# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
847Zone America/Boise	-7:44:49 -	LMT	1883 Nov 18 12:15:11
848			-8:00	US	P%sT	1923 May 13  2:00
849			-7:00	US	M%sT	1974
850			-7:00	-	MST	1974 Feb  3  2:00
851			-7:00	US	M%sT
852
853# Indiana
854#
855# For a map of Indiana's time zone regions, see:
856# https://en.wikipedia.org/wiki/Time_in_Indiana
857#
858# From Paul Eggert (2018-11-30):
859# A brief but entertaining history of time in Indiana describes a 1949 debate
860# in the Indiana House where city legislators (who favored "fast time")
861# tussled with farm legislators (who didn't) over a bill to outlaw DST:
862#  "Lacking enough votes, the city faction tries to filibuster until time runs
863#   out on the session at midnight, but rural champion Rep. Herbert Copeland,
864#   R-Madison, leans over the gallery railing and forces the official clock
865#   back to 9 p.m., breaking it in the process.  The clock sticks on 9 as the
866#   debate rages on into the night.  The filibuster finally dies out and the
867#   bill passes, while outside the chamber, clocks read 3:30 a.m.  In the end,
868#   it doesn't matter which side won.  The law has no enforcement powers and
869#   is simply ignored by fast-time communities."
870# How Indiana went from 'God's time' to split zones and daylight-saving.
871# Indianapolis Star. 2018-11-27 14:58 -05.
872# https://www.indystar.com/story/news/politics/2018/11/27/indianapolis-indiana-time-zone-history-central-eastern-daylight-savings-time/2126300002/
873#
874# From Paul Eggert (2007-08-17):
875# Since 1970, most of Indiana has been like America/Indiana/Indianapolis,
876# with the following exceptions:
877#
878# - Gibson, Jasper, Lake, LaPorte, Newton, Porter, Posey, Spencer,
879#   Vanderburgh, and Warrick counties have been like America/Chicago.
880#
881# - Dearborn and Ohio counties have been like America/New_York.
882#
883# - Clark, Floyd, and Harrison counties have been like
884#   America/Kentucky/Louisville.
885#
886# - Crawford, Daviess, Dubois, Knox, Martin, Perry, Pike, Pulaski, Starke,
887#   and Switzerland counties have their own time zone histories as noted below.
888#
889# Shanks partitioned Indiana into 345 regions, each with its own time history,
890# and wrote "Even newspaper reports present contradictory information."
891# Those Hoosiers!  Such a flighty and changeable people!
892# Fortunately, most of the complexity occurred before our cutoff date of 1970.
893#
894# Other than Indianapolis, the Indiana place names are so nondescript
895# that they would be ambiguous if we left them at the 'America' level.
896# So we reluctantly put them all in a subdirectory 'America/Indiana'.
897
898# From Paul Eggert (2014-06-26):
899# https://www.federalregister.gov/articles/2006/01/20/06-563/standard-time-zone-boundary-in-the-state-of-indiana
900# says "DOT is relocating the time zone boundary in Indiana to move Starke,
901# Pulaski, Knox, Daviess, Martin, Pike, Dubois, and Perry Counties from the
902# Eastern Time Zone to the Central Time Zone.... The effective date of
903# this rule is 2 a.m. EST Sunday, April 2, 2006, which is the
904# changeover date from standard time to Daylight Saving Time."
905# Strictly speaking, this meant the affected counties changed their
906# clocks twice that night, but this obviously was in error.  The intent
907# was that 01:59:59 EST be followed by 02:00:00 CDT.
908
909# From Gwillim Law (2007-02-10):
910# The Associated Press has been reporting that Pulaski County, Indiana is
911# going to switch from Central to Eastern Time on March 11, 2007....
912# http://www.indystar.com/apps/pbcs.dll/article?AID=/20070207/LOCAL190108/702070524/0/LOCAL
913
914# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
915Rule Indianapolis 1941	only	-	Jun	22	2:00	1:00	D
916Rule Indianapolis 1941	1954	-	Sep	lastSun	2:00	0	S
917Rule Indianapolis 1946	1954	-	Apr	lastSun	2:00	1:00	D
918# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
919Zone America/Indiana/Indianapolis -5:44:38 - LMT	1883 Nov 18 12:15:22
920			-6:00	US	C%sT	1920
921			-6:00 Indianapolis C%sT	1942
922			-6:00	US	C%sT	1946
923			-6:00 Indianapolis C%sT	1955 Apr 24  2:00
924			-5:00	-	EST	1957 Sep 29  2:00
925			-6:00	-	CST	1958 Apr 27  2:00
926			-5:00	-	EST	1969
927			-5:00	US	E%sT	1971
928			-5:00	-	EST	2006
929			-5:00	US	E%sT
930#
931# Eastern Crawford County, Indiana, left its clocks alone in 1974,
932# as well as from 1976 through 2005.
933# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
934Rule	Marengo	1951	only	-	Apr	lastSun	2:00	1:00	D
935Rule	Marengo	1951	only	-	Sep	lastSun	2:00	0	S
936Rule	Marengo	1954	1960	-	Apr	lastSun	2:00	1:00	D
937Rule	Marengo	1954	1960	-	Sep	lastSun	2:00	0	S
938# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
939Zone America/Indiana/Marengo -5:45:23 -	LMT	1883 Nov 18 12:14:37
940			-6:00	US	C%sT	1951
941			-6:00	Marengo	C%sT	1961 Apr 30  2:00
942			-5:00	-	EST	1969
943			-5:00	US	E%sT	1974 Jan  6  2:00
944			-6:00	1:00	CDT	1974 Oct 27  2:00
945			-5:00	US	E%sT	1976
946			-5:00	-	EST	2006
947			-5:00	US	E%sT
948#
949# Daviess, Dubois, Knox, and Martin Counties, Indiana,
950# switched from eastern to central time in April 2006, then switched back
951# in November 2007.
952# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
953Rule Vincennes	1946	only	-	Apr	lastSun	2:00	1:00	D
954Rule Vincennes	1946	only	-	Sep	lastSun	2:00	0	S
955Rule Vincennes	1953	1954	-	Apr	lastSun	2:00	1:00	D
956Rule Vincennes	1953	1959	-	Sep	lastSun	2:00	0	S
957Rule Vincennes	1955	only	-	May	 1	0:00	1:00	D
958Rule Vincennes	1956	1963	-	Apr	lastSun	2:00	1:00	D
959Rule Vincennes	1960	only	-	Oct	lastSun	2:00	0	S
960Rule Vincennes	1961	only	-	Sep	lastSun	2:00	0	S
961Rule Vincennes	1962	1963	-	Oct	lastSun	2:00	0	S
962# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
963Zone America/Indiana/Vincennes -5:50:07 - LMT	1883 Nov 18 12:09:53
964			-6:00	US	C%sT	1946
965			-6:00 Vincennes	C%sT	1964 Apr 26  2:00
966			-5:00	-	EST	1969
967			-5:00	US	E%sT	1971
968			-5:00	-	EST	2006 Apr  2  2:00
969			-6:00	US	C%sT	2007 Nov  4  2:00
970			-5:00	US	E%sT
971#
972# Perry County, Indiana, switched from eastern to central time in April 2006.
973# From Alois Triendl (2019-07-09):
974# The Indianapolis News, Friday 27 October 1967 states that Perry County
975# returned to CST.  It went again to EST on 27 April 1969, as documented by the
976# Indianapolis star of Saturday 26 April.
977# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
978Rule Perry	1955	only	-	May	 1	0:00	1:00	D
979Rule Perry	1955	1960	-	Sep	lastSun	2:00	0	S
980Rule Perry	1956	1963	-	Apr	lastSun	2:00	1:00	D
981Rule Perry	1961	1963	-	Oct	lastSun	2:00	0	S
982# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
983Zone America/Indiana/Tell_City -5:47:03 - LMT	1883 Nov 18 12:12:57
984			-6:00	US	C%sT	1946
985			-6:00 Perry	C%sT	1964 Apr 26  2:00
986			-5:00	-	EST	1967 Oct 29  2:00
987			-6:00	US	C%sT	1969 Apr 27  2:00
988			-5:00	US	E%sT	1971
989			-5:00	-	EST	2006 Apr  2  2:00
990			-6:00	US	C%sT
991#
992# Pike County, Indiana moved from central to eastern time in 1977,
993# then switched back in 2006, then switched back again in 2007.
994# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
995Rule	Pike	1955	only	-	May	 1	0:00	1:00	D
996Rule	Pike	1955	1960	-	Sep	lastSun	2:00	0	S
997Rule	Pike	1956	1964	-	Apr	lastSun	2:00	1:00	D
998Rule	Pike	1961	1964	-	Oct	lastSun	2:00	0	S
999# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
1000Zone America/Indiana/Petersburg -5:49:07 - LMT	1883 Nov 18 12:10:53
1001			-6:00	US	C%sT	1955
1002			-6:00	Pike	C%sT	1965 Apr 25  2:00
1003			-5:00	-	EST	1966 Oct 30  2:00
1004			-6:00	US	C%sT	1977 Oct 30  2:00
1005			-5:00	-	EST	2006 Apr  2  2:00
1006			-6:00	US	C%sT	2007 Nov  4  2:00
1007			-5:00	US	E%sT
1008#
1009# Starke County, Indiana moved from central to eastern time in 1991,
1010# then switched back in 2006.
1011# From Arthur David Olson (1991-10-28):
1012# An article on page A3 of the Sunday, 1991-10-27 Washington Post
1013# notes that Starke County switched from Central time to Eastern time as of
1014# 1991-10-27.
1015# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
1016Rule	Starke	1947	1961	-	Apr	lastSun	2:00	1:00	D
1017Rule	Starke	1947	1954	-	Sep	lastSun	2:00	0	S
1018Rule	Starke	1955	1956	-	Oct	lastSun	2:00	0	S
1019Rule	Starke	1957	1958	-	Sep	lastSun	2:00	0	S
1020Rule	Starke	1959	1961	-	Oct	lastSun	2:00	0	S
1021# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
1022Zone America/Indiana/Knox -5:46:30 -	LMT	1883 Nov 18 12:13:30
1023			-6:00	US	C%sT	1947
1024			-6:00	Starke	C%sT	1962 Apr 29  2:00
1025			-5:00	-	EST	1963 Oct 27  2:00
1026			-6:00	US	C%sT	1991 Oct 27  2:00
1027			-5:00	-	EST	2006 Apr  2  2:00
1028			-6:00	US	C%sT
1029#
1030# Pulaski County, Indiana, switched from eastern to central time in
1031# April 2006 and then switched back in March 2007.
1032# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
1033Rule	Pulaski	1946	1960	-	Apr	lastSun	2:00	1:00	D
1034Rule	Pulaski	1946	1954	-	Sep	lastSun	2:00	0	S
1035Rule	Pulaski	1955	1956	-	Oct	lastSun	2:00	0	S
1036Rule	Pulaski	1957	1960	-	Sep	lastSun	2:00	0	S
1037# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
1038Zone America/Indiana/Winamac -5:46:25 - LMT	1883 Nov 18 12:13:35
1039			-6:00	US	C%sT	1946
1040			-6:00	Pulaski	C%sT	1961 Apr 30  2:00
1041			-5:00	-	EST	1969
1042			-5:00	US	E%sT	1971
1043			-5:00	-	EST	2006 Apr  2  2:00
1044			-6:00	US	C%sT	2007 Mar 11  2:00
1045			-5:00	US	E%sT
1046#
1047# Switzerland County, Indiana, did not observe DST from 1973 through 2005.
1048# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
1049Zone America/Indiana/Vevay -5:40:16 -	LMT	1883 Nov 18 12:19:44
1050			-6:00	US	C%sT	1954 Apr 25  2:00
1051			-5:00	-	EST	1969
1052			-5:00	US	E%sT	1973
1053			-5:00	-	EST	2006
1054			-5:00	US	E%sT
1055
1056# From Paul Eggert (2018-03-20):
1057# The Louisville & Nashville Railroad's 1883-11-18 change occurred at
1058# 10:00 old local time; train were supposed to come to a standstill
1059# for precisely 18 minutes.  See Bartky Fig. 1 (page 50).  It is not
1060# clear how this matched civil time in Louisville, so for now continue
1061# to assume Louisville switched at noon new local time, like New York.
1062#
1063# From Michael Deckers (2019-08-06):
1064# From the contemporary source given by Alois Treindl,
1065# the switch in Louisville on 1946-04-28 was on 00:01
1066# From Paul Eggert (2019-08-26):
1067# That source was the Louisville Courier-Journal, 1946-04-27, p 4.
1068# Shanks gives 02:00 for all 20th-century transition times in Louisville.
1069# Evidently this is wrong for spring 1946.  Although also likely wrong
1070# for other dates, we have no data.
1071#
1072# Part of Kentucky left its clocks alone in 1974.
1073# This also includes Clark, Floyd, and Harrison counties in Indiana.
1074# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
1075Rule Louisville	1921	only	-	May	1	2:00	1:00	D
1076Rule Louisville	1921	only	-	Sep	1	2:00	0	S
1077Rule Louisville	1941	only	-	Apr	lastSun	2:00	1:00	D
1078Rule Louisville	1941	only	-	Sep	lastSun	2:00	0	S
1079Rule Louisville	1946	only	-	Apr	lastSun	0:01	1:00	D
1080Rule Louisville	1946	only	-	Jun	2	2:00	0	S
1081Rule Louisville	1950	1961	-	Apr	lastSun	2:00	1:00	D
1082Rule Louisville	1950	1955	-	Sep	lastSun	2:00	0	S
1083Rule Louisville	1956	1961	-	Oct	lastSun	2:00	0	S
1084# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
1085Zone America/Kentucky/Louisville -5:43:02 -	LMT	1883 Nov 18 12:16:58
1086			-6:00	US	C%sT	1921
1087			-6:00 Louisville C%sT	1942
1088			-6:00	US	C%sT	1946
1089			-6:00 Louisville C%sT	1961 Jul 23  2:00
1090			-5:00	-	EST	1968
1091			-5:00	US	E%sT	1974 Jan  6  2:00
1092			-6:00	1:00	CDT	1974 Oct 27  2:00
1093			-5:00	US	E%sT
1094#
1095# Wayne County, Kentucky
1096#
1097# From Lake Cumberland LIFE
1098# http://www.lake-cumberland.com/life/archive/news990129time.shtml
1099# (1999-01-29) via WKYM-101.7:
1100# Clinton County has joined Wayne County in asking the DoT to change from
1101# the Central to the Eastern time zone....  The Wayne County government made
1102# the same request in December.  And while Russell County officials have not
1103# taken action, the majority of respondents to a poll conducted there in
1104# August indicated they would like to change to "fast time" also.
1105# The three Lake Cumberland counties are the farthest east of any U.S.
1106# location in the Central time zone.
1107#
1108# From Rich Wales (2000-08-29):
1109# After prolonged debate, and despite continuing deep differences of opinion,
1110# Wayne County (central Kentucky) is switching from Central (-0600) to Eastern
1111# (-0500) time.  They won't "fall back" this year.  See Sara Shipley,
1112# The difference an hour makes, Nando Times (2000-08-29 15:33 -0400).
1113#
1114# From Paul Eggert (2001-07-16):
1115# The final rule was published in the
1116# Federal Register 65, 160 (2000-08-17), pp 50154-50158.
1117# https://www.gpo.gov/fdsys/pkg/FR-2000-08-17/html/00-20854.htm
1118#
1119Zone America/Kentucky/Monticello -5:39:24 - LMT	1883 Nov 18 12:20:36
1120			-6:00	US	C%sT	1946
1121			-6:00	-	CST	1968
1122			-6:00	US	C%sT	2000 Oct 29  2:00
1123			-5:00	US	E%sT
1124
1125
1126# From Rives McDow (2000-08-30):
1127# Here ... are all the changes in the US since 1985.
1128# Kearny County, KS (put all of county on central;
1129#	previously split between MST and CST) ... 1990-10
1130# Starke County, IN (from CST to EST) ... 1991-10
1131# Oliver County, ND (from MST to CST) ... 1992-10
1132# West Wendover, NV (from PST TO MST) ... 1999-10
1133# Wayne County, KY (from CST to EST) ... 2000-10
1134#
1135# From Paul Eggert (2001-07-17):
1136# We don't know where the line used to be within Kearny County, KS,
1137# so omit that change for now.
1138# See America/Indiana/Knox for the Starke County, IN change.
1139# See America/North_Dakota/Center for the Oliver County, ND change.
1140# West Wendover, NV officially switched from Pacific to mountain time on
1141# 1999-10-31.  See the
1142# Federal Register 64, 203 (1999-10-21), pp 56705-56707.
1143# https://www.gpo.gov/fdsys/pkg/FR-1999-10-21/html/99-27240.htm
1144# However, the Federal Register says that West Wendover already operated
1145# on mountain time, and the rule merely made this official;
1146# hence a separate tz entry is not needed.
1147
1148# Michigan
1149#
1150# From Bob Devine (1988-01-28):
1151# Michigan didn't observe DST from 1968 to 1973.
1152#
1153# From Paul Eggert (1999-03-31):
1154# Shanks writes that Michigan started using standard time on 1885-09-18,
1155# but Howse writes (pp 124-125, referring to Popular Astronomy, 1901-01)
1156# that Detroit kept
1157#
1158#	local time until 1900 when the City Council decreed that clocks should
1159#	be put back twenty-eight minutes to Central Standard Time.  Half the
1160#	city obeyed, half refused.  After considerable debate, the decision
1161#	was rescinded and the city reverted to Sun time.  A derisive offer to
1162#	erect a sundial in front of the city hall was referred to the
1163#	Committee on Sewers.  Then, in 1905, Central time was adopted
1164#	by city vote.
1165#
1166# This story is too entertaining to be false, so go with Howse over Shanks.
1167#
1168# From Paul Eggert (2001-03-06):
1169# Garland (1927) writes "Cleveland and Detroit advanced their clocks
1170# one hour in 1914."  This change is not in Shanks.  We have no more
1171# info, so omit this for now.
1172#
1173# From Paul Eggert (2019-07-06):
1174# Due to a complicated set of legal maneuvers, in 1967 Michigan did
1175# not start daylight saving time when the rest of the US did.
1176# Instead, it began DST on Jun 14 at 00:01.  This was big news:
1177# the Detroit Free Press reported it at the top of Page 1 on
1178# 1967-06-14, in an article "State Adjusting to Switch to Fast Time"
1179# by Gary Blonston, above an article about Thurgood Marshall's
1180# confirmation to the US Supreme Court.  Although Shanks says Detroit
1181# observed DST until 1967-10-29 00:01, that time of day seems to be
1182# incorrect, as the Free Press later said DST ended in Michigan at the
1183# same time as the rest of the US.  Also, although Shanks reports no DST in
1184# Detroit in 1968, it did observe DST that year; in the November 1968
1185# election Michigan voters narrowly repealed DST, effective 1969.
1186#
1187# Most of Michigan observed DST from 1973 on, but was a bit late in 1975.
1188# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
1189Rule	Detroit	1948	only	-	Apr	lastSun	2:00	1:00	D
1190Rule	Detroit	1948	only	-	Sep	lastSun	2:00	0	S
1191# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
1192Zone America/Detroit	-5:32:11 -	LMT	1905
1193			-6:00	-	CST	1915 May 15  2:00
1194			-5:00	-	EST	1942
1195			-5:00	US	E%sT	1946
1196			-5:00	Detroit	E%sT	1967 Jun 14  0:01
1197			-5:00	US	E%sT	1969
1198			-5:00	-	EST	1973
1199			-5:00	US	E%sT	1975
1200			-5:00	-	EST	1975 Apr 27  2:00
1201			-5:00	US	E%sT
1202#
1203# Dickinson, Gogebic, Iron, and Menominee Counties, Michigan,
1204# switched from EST to CST/CDT in 1973.
1205# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
1206Rule Menominee	1946	only	-	Apr	lastSun	2:00	1:00	D
1207Rule Menominee	1946	only	-	Sep	lastSun	2:00	0	S
1208Rule Menominee	1966	only	-	Apr	lastSun	2:00	1:00	D
1209Rule Menominee	1966	only	-	Oct	lastSun	2:00	0	S
1210# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
1211Zone America/Menominee	-5:50:27 -	LMT	1885 Sep 18 12:00
1212			-6:00	US	C%sT	1946
1213			-6:00 Menominee	C%sT	1969 Apr 27  2:00
1214			-5:00	-	EST	1973 Apr 29  2:00
1215			-6:00	US	C%sT
1216
1217# Navassa
1218# administered by the US Fish and Wildlife Service
1219# claimed by US under the provisions of the 1856 Guano Islands Act
1220# also claimed by Haiti
1221# occupied 1857/1900 by the Navassa Phosphate Co
1222# US lighthouse 1917/1996-09
1223# currently uninhabited
1224# see Mark Fineman, "An Isle Rich in Guano and Discord",
1225# _Los Angeles Times_ (1998-11-10), A1, A10; it cites
1226# Jimmy Skaggs, _The Great Guano Rush_ (1994).
1227
1228################################################################################
1229
1230
1231# From Paul Eggert (2017-02-10):
1232#
1233# Unless otherwise specified, the source for data through 1990 is:
1234# Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition),
1235# San Diego: ACS Publications, Inc. (2003).
1236# Unfortunately this book contains many errors and cites no sources.
1237#
1238# Many years ago Gwillim Law wrote that a good source
1239# for time zone data was the International Air Transport
1240# Association's Standard Schedules Information Manual (IATA SSIM),
1241# published semiannually.  Law sent in several helpful summaries
1242# of the IATA's data after 1990.  Except where otherwise noted,
1243# IATA SSIM is the source for entries after 1990.
1244#
1245# Other sources occasionally used include:
1246#
1247#	Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94
1248#	<https://www.jstor.org/stable/1774359>.
1249#
1250#	Pearce C. The Great Daylight Saving Time Controversy.
1251#	Australian Ebook Publisher. 2017. ISBN 978-1-925516-96-8.
1252#
1253#	Edward W. Whitman, World Time Differences,
1254#	Whitman Publishing Co, 2 Niagara Av, Ealing, London (undated),
1255#	which I found in the UCLA library.
1256#
1257#	William Willett, The Waste of Daylight, 19th edition
1258#	<http://cs.ucla.edu/~eggert/The-Waste-of-Daylight-19th.pdf>
1259#	[PDF] (1914-03)
1260#
1261# See the 'europe' file for Greenland.
1262
1263# Canada
1264
1265# From Alain LaBonté (1994-11-14):
1266# I post here the time zone abbreviations standardized in Canada
1267# for both English and French in the CAN/CSA-Z234.4-89 standard....
1268#
1269#	UTC	Standard time	Daylight saving time
1270#	offset	French	English	French	English
1271#	-2:30	-	-	HAT	NDT
1272#	-3	-	-	HAA	ADT
1273#	-3:30	HNT	NST	-	-
1274#	-4	HNA	AST	HAE	EDT
1275#	-5	HNE	EST	HAC	CDT
1276#	-6	HNC	CST	HAR	MDT
1277#	-7	HNR	MST	HAP	PDT
1278#	-8	HNP	PST	HAY	YDT
1279#	-9	HNY	YST	-	-
1280#
1281#	HN: Heure Normale	ST: Standard Time
1282#	HA: Heure Avancée	DT: Daylight saving Time
1283#
1284#	A: de l'Atlantique	Atlantic
1285#	C: du Centre		Central
1286#	E: de l'Est		Eastern
1287#	M:			Mountain
1288#	N:			Newfoundland
1289#	P: du Pacifique		Pacific
1290#	R: des Rocheuses
1291#	T: de Terre-Neuve
1292#	Y: du Yukon		Yukon
1293#
1294# From Paul Eggert (1994-11-22):
1295# Alas, this sort of thing must be handled by localization software.
1296
1297# Unless otherwise specified, the data entries for Canada are all from Shanks
1298# & Pottenger.
1299
1300# From Chris Walton (2006-04-01, 2006-04-25, 2006-06-26, 2007-01-31,
1301# 2007-03-01):
1302# The British Columbia government announced yesterday that it will
1303# adjust daylight savings next year to align with changes in the
1304# U.S. and the rest of Canada....
1305# https://archive.news.gov.bc.ca/releases/news_releases_2005-2009/2006AG0014-000330.htm
1306# ...
1307# Nova Scotia
1308# Daylight saving time will be extended by four weeks starting in 2007....
1309# https://www.novascotia.ca/just/regulations/rg2/2006/ma1206.pdf
1310#
1311# [For New Brunswick] the new legislation dictates that the time change is to
1312# be done at 02:00 instead of 00:01.
1313# https://www.gnb.ca/0062/acts/BBA-2006/Chap-19.pdf
1314# ...
1315# Manitoba has traditionally changed the clock every fall at 03:00.
1316# As of 2006, the transition is to take place one hour earlier at 02:00.
1317# https://web2.gov.mb.ca/laws/statutes/ccsm/o030e.php
1318# ...
1319# [Alberta, Ontario, Quebec] will follow US rules.
1320# http://www.qp.gov.ab.ca/documents/spring/CH03_06.CFM
1321# http://www.e-laws.gov.on.ca/DBLaws/Source/Regs/English/2006/R06111_e.htm
1322# http://www2.publicationsduquebec.gouv.qc.ca/dynamicSearch/telecharge.php?type=5&file=2006C39A.PDF
1323# ...
1324# P.E.I. will follow US rules....
1325# http://www.assembly.pe.ca/bills/pdf_chapter/62/3/chapter-41.pdf
1326# ...
1327# Province of Newfoundland and Labrador....
1328# http://www.hoa.gov.nl.ca/hoa/bills/Bill0634.htm
1329# ...
1330# Yukon
1331# https://www.gov.yk.ca/legislation/regs/oic2006_127.pdf
1332# ...
1333# N.W.T. will follow US rules.  Whoever maintains the government web site
1334# does not seem to believe in bookmarks.  To see the news release, click the
1335# following link and search for "Daylight Savings Time Change".  Press the
1336# "Daylight Savings Time Change" link; it will fire off a popup using
1337# JavaScript.
1338# http://www.exec.gov.nt.ca/currentnews/currentPR.asp?mode=archive
1339# ...
1340# Nunavut
1341# An amendment to the Interpretation Act was registered on February 19/2007....
1342# http://action.attavik.ca/home/justice-gn/attach/2007/gaz02part2.pdf
1343
1344# From Paul Eggert (2014-10-18):
1345# H. David Matthews and Mary Vincent's map
1346# "It's about TIME", _Canadian Geographic_ (September-October 1998)
1347# http://www.canadiangeographic.ca/Magazine/SO98/alacarte.asp
1348# contains detailed boundaries for regions observing nonstandard
1349# time and daylight saving time arrangements in Canada circa 1998.
1350#
1351# National Research Council Canada maintains info about time zones and DST.
1352# https://www.nrc-cnrc.gc.ca/eng/services/time/time_zones.html
1353# https://www.nrc-cnrc.gc.ca/eng/services/time/faq/index.html#Q5
1354# Its unofficial information is often taken from Matthews and Vincent.
1355
1356# From Paul Eggert (2006-06-27):
1357# For now, assume all of DST-observing Canada will fall into line with the
1358# new US DST rules,
1359
1360# From Chris Walton (2011-12-01)
1361# In the first of Tammy Hardwick's articles
1362# http://www.ilovecreston.com/?p=articles&t=spec&ar=260
1363# she quotes the Friday November 1/1918 edition of the Creston Review.
1364# The quote includes these two statements:
1365# 'Sunday the CPR went back to the old system of time...'
1366# '... The daylight saving scheme was dropped all over Canada at the same time,'
1367# These statements refer to a transition from daylight time to standard time
1368# that occurred nationally on Sunday October 27/1918.  This transition was
1369# also documented in the Saturday October 26/1918 edition of the Toronto Star.
1370
1371# In light of that evidence, we alter the date from the earlier believed
1372# Oct 31, to Oct 27, 1918 (and Sunday is a more likely transition day
1373# than Thursday) in all Canadian rulesets.
1374
1375# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
1376Rule	Canada	1918	only	-	Apr	14	2:00	1:00	D
1377Rule	Canada	1918	only	-	Oct	27	2:00	0	S
1378Rule	Canada	1942	only	-	Feb	 9	2:00	1:00	W # War
1379Rule	Canada	1945	only	-	Aug	14	23:00u	1:00	P # Peace
1380Rule	Canada	1945	only	-	Sep	30	2:00	0	S
1381Rule	Canada	1974	1986	-	Apr	lastSun	2:00	1:00	D
1382Rule	Canada	1974	2006	-	Oct	lastSun	2:00	0	S
1383Rule	Canada	1987	2006	-	Apr	Sun>=1	2:00	1:00	D
1384Rule	Canada	2007	max	-	Mar	Sun>=8	2:00	1:00	D
1385Rule	Canada	2007	max	-	Nov	Sun>=1	2:00	0	S
1386
1387
1388# Newfoundland and Labrador
1389
1390# From Paul Eggert (2017-10-14):
1391# Legally Labrador should observe Newfoundland time; see:
1392# McLeod J. Labrador time - legal or not? St. John's Telegram, 2017-10-07
1393# http://www.thetelegram.com/news/local/labrador-time--legal-or-not-154860/
1394# Matthews and Vincent (1998) write that the only part of Labrador
1395# that follows the rules is the southeast corner, including Port Hope
1396# Simpson and Mary's Harbour, but excluding, say, Black Tickle.
1397
1398# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
1399Rule	StJohns	1917	only	-	Apr	 8	2:00	1:00	D
1400Rule	StJohns	1917	only	-	Sep	17	2:00	0	S
1401# Whitman gives 1919 Apr 5 and 1920 Apr 5; go with Shanks & Pottenger.
1402Rule	StJohns	1919	only	-	May	 5	23:00	1:00	D
1403Rule	StJohns	1919	only	-	Aug	12	23:00	0	S
1404# For 1931-1935 Whitman gives Apr same date; go with Shanks & Pottenger.
1405Rule	StJohns	1920	1935	-	May	Sun>=1	23:00	1:00	D
1406Rule	StJohns	1920	1935	-	Oct	lastSun	23:00	0	S
1407# For 1936-1941 Whitman gives May Sun>=8 and Oct Sun>=1; go with Shanks &
1408# Pottenger.
1409Rule	StJohns	1936	1941	-	May	Mon>=9	0:00	1:00	D
1410Rule	StJohns	1936	1941	-	Oct	Mon>=2	0:00	0	S
1411# Whitman gives the following transitions:
1412# 1942 03-01/12-31, 1943 05-30/09-05, 1944 07-10/09-02, 1945 01-01/10-07
1413# but go with Shanks & Pottenger and assume they used Canadian rules.
1414# For 1946-9 Whitman gives May 5,4,9,1 - Oct 1,5,3,2, and for 1950 he gives
1415# Apr 30 - Sep 24; go with Shanks & Pottenger.
1416Rule	StJohns	1946	1950	-	May	Sun>=8	2:00	1:00	D
1417Rule	StJohns	1946	1950	-	Oct	Sun>=2	2:00	0	S
1418Rule	StJohns	1951	1986	-	Apr	lastSun	2:00	1:00	D
1419Rule	StJohns	1951	1959	-	Sep	lastSun	2:00	0	S
1420Rule	StJohns	1960	1986	-	Oct	lastSun	2:00	0	S
1421# From Paul Eggert (2000-10-02):
1422# INMS (2000-09-12) says that, since 1988 at least, Newfoundland switches
1423# at 00:01 local time.  For now, assume it started in 1987.
1424
1425# From Michael Pelley (2011-09-12):
1426# We received today, Monday, September 12, 2011, notification that the
1427# changes to the Newfoundland Standard Time Act have been proclaimed.
1428# The change in the Act stipulates that the change from Daylight Savings
1429# Time to Standard Time and from Standard Time to Daylight Savings Time
1430# now occurs at 2:00AM.
1431# ...
1432# http://www.assembly.nl.ca/legislation/sr/annualstatutes/2011/1106.chp.htm
1433# ...
1434# MICHAEL PELLEY  |  Manager of Enterprise Architecture - Solution Delivery
1435# Office of the Chief Information Officer
1436# Executive Council
1437# Government of Newfoundland & Labrador
1438
1439Rule	StJohns	1987	only	-	Apr	Sun>=1	0:01	1:00	D
1440Rule	StJohns	1987	2006	-	Oct	lastSun	0:01	0	S
1441Rule	StJohns	1988	only	-	Apr	Sun>=1	0:01	2:00	DD
1442Rule	StJohns	1989	2006	-	Apr	Sun>=1	0:01	1:00	D
1443Rule	StJohns	2007	2011	-	Mar	Sun>=8	0:01	1:00	D
1444Rule	StJohns	2007	2010	-	Nov	Sun>=1	0:01	0	S
1445#
1446# St John's has an apostrophe, but Posix file names can't have apostrophes.
1447# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
1448Zone America/St_Johns	-3:30:52 -	LMT	1884
1449			-3:30:52 StJohns N%sT	1918
1450			-3:30:52 Canada	N%sT	1919
1451			-3:30:52 StJohns N%sT	1935 Mar 30
1452			-3:30	StJohns	N%sT	1942 May 11
1453			-3:30	Canada	N%sT	1946
1454			-3:30	StJohns	N%sT	2011 Nov
1455			-3:30	Canada	N%sT
1456
1457# most of east Labrador
1458
1459# The name 'Happy Valley-Goose Bay' is too long; use 'Goose Bay'.
1460# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
1461Zone America/Goose_Bay	-4:01:40 -	LMT	1884 # Happy Valley-Goose Bay
1462			-3:30:52 -	NST	1918
1463			-3:30:52 Canada N%sT	1919
1464			-3:30:52 -	NST	1935 Mar 30
1465			-3:30	-	NST	1936
1466			-3:30	StJohns	N%sT	1942 May 11
1467			-3:30	Canada	N%sT	1946
1468			-3:30	StJohns	N%sT	1966 Mar 15  2:00
1469			-4:00	StJohns	A%sT	2011 Nov
1470			-4:00	Canada	A%sT
1471
1472
1473# west Labrador, Nova Scotia, Prince Edward I,
1474# Îles-de-la-Madeleine, Listuguj reserve
1475
1476# From Brian Inglis (2015-07-20):
1477# From the historical weather station records available at:
1478# https://weatherspark.com/history/28351/1971/Sydney-Nova-Scotia-Canada
1479# Sydney shares the same time history as Glace Bay, so was
1480# likely to be the same across the island....
1481# Sydney, as the capital and most populous location, or Cape Breton, would
1482# have been better names for the zone had we known this in 1996.
1483
1484# From Paul Eggert (2015-07-20):
1485# Shanks & Pottenger write that since 1970 most of this region has been like
1486# Halifax.  Many locales did not observe peacetime DST until 1972;
1487# the Cape Breton area, represented by Glace Bay, is the largest we know of
1488# (Glace Bay was perhaps not the best name choice but no point changing now).
1489# Shanks & Pottenger also write that Liverpool, NS was the only town
1490# in Canada to observe DST in 1971 but not 1970; for now we'll assume
1491# this is a typo.
1492
1493# From Jeffery Nichols (2020-01-09):
1494# America/Halifax ... also applies to Îles-de-la-Madeleine and the Listuguj
1495# reserve in Quebec. Officially, this came into effect on January 1, 2007
1496# (Legal Time Act, CQLR c T-5.1), but the legislative debates surrounding that
1497# bill say that it is "accommodating the customs and practices" of those
1498# regions, which suggests that they have always been in-line with Halifax.
1499
1500# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
1501Rule	Halifax	1916	only	-	Apr	 1	0:00	1:00	D
1502Rule	Halifax	1916	only	-	Oct	 1	0:00	0	S
1503Rule	Halifax	1920	only	-	May	 9	0:00	1:00	D
1504Rule	Halifax	1920	only	-	Aug	29	0:00	0	S
1505Rule	Halifax	1921	only	-	May	 6	0:00	1:00	D
1506Rule	Halifax	1921	1922	-	Sep	 5	0:00	0	S
1507Rule	Halifax	1922	only	-	Apr	30	0:00	1:00	D
1508Rule	Halifax	1923	1925	-	May	Sun>=1	0:00	1:00	D
1509Rule	Halifax	1923	only	-	Sep	 4	0:00	0	S
1510Rule	Halifax	1924	only	-	Sep	15	0:00	0	S
1511Rule	Halifax	1925	only	-	Sep	28	0:00	0	S
1512Rule	Halifax	1926	only	-	May	16	0:00	1:00	D
1513Rule	Halifax	1926	only	-	Sep	13	0:00	0	S
1514Rule	Halifax	1927	only	-	May	 1	0:00	1:00	D
1515Rule	Halifax	1927	only	-	Sep	26	0:00	0	S
1516Rule	Halifax	1928	1931	-	May	Sun>=8	0:00	1:00	D
1517Rule	Halifax	1928	only	-	Sep	 9	0:00	0	S
1518Rule	Halifax	1929	only	-	Sep	 3	0:00	0	S
1519Rule	Halifax	1930	only	-	Sep	15	0:00	0	S
1520Rule	Halifax	1931	1932	-	Sep	Mon>=24	0:00	0	S
1521Rule	Halifax	1932	only	-	May	 1	0:00	1:00	D
1522Rule	Halifax	1933	only	-	Apr	30	0:00	1:00	D
1523Rule	Halifax	1933	only	-	Oct	 2	0:00	0	S
1524Rule	Halifax	1934	only	-	May	20	0:00	1:00	D
1525Rule	Halifax	1934	only	-	Sep	16	0:00	0	S
1526Rule	Halifax	1935	only	-	Jun	 2	0:00	1:00	D
1527Rule	Halifax	1935	only	-	Sep	30	0:00	0	S
1528Rule	Halifax	1936	only	-	Jun	 1	0:00	1:00	D
1529Rule	Halifax	1936	only	-	Sep	14	0:00	0	S
1530Rule	Halifax	1937	1938	-	May	Sun>=1	0:00	1:00	D
1531Rule	Halifax	1937	1941	-	Sep	Mon>=24	0:00	0	S
1532Rule	Halifax	1939	only	-	May	28	0:00	1:00	D
1533Rule	Halifax	1940	1941	-	May	Sun>=1	0:00	1:00	D
1534Rule	Halifax	1946	1949	-	Apr	lastSun	2:00	1:00	D
1535Rule	Halifax	1946	1949	-	Sep	lastSun	2:00	0	S
1536Rule	Halifax	1951	1954	-	Apr	lastSun	2:00	1:00	D
1537Rule	Halifax	1951	1954	-	Sep	lastSun	2:00	0	S
1538Rule	Halifax	1956	1959	-	Apr	lastSun	2:00	1:00	D
1539Rule	Halifax	1956	1959	-	Sep	lastSun	2:00	0	S
1540Rule	Halifax	1962	1973	-	Apr	lastSun	2:00	1:00	D
1541Rule	Halifax	1962	1973	-	Oct	lastSun	2:00	0	S
1542# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
1543Zone America/Halifax	-4:14:24 -	LMT	1902 Jun 15
1544			-4:00	Halifax	A%sT	1918
1545			-4:00	Canada	A%sT	1919
1546			-4:00	Halifax	A%sT	1942 Feb  9  2:00s
1547			-4:00	Canada	A%sT	1946
1548			-4:00	Halifax	A%sT	1974
1549			-4:00	Canada	A%sT
1550Zone America/Glace_Bay	-3:59:48 -	LMT	1902 Jun 15
1551			-4:00	Canada	A%sT	1953
1552			-4:00	Halifax	A%sT	1954
1553			-4:00	-	AST	1972
1554			-4:00	Halifax	A%sT	1974
1555			-4:00	Canada	A%sT
1556
1557# New Brunswick
1558
1559# From Paul Eggert (2007-01-31):
1560# The Time Definition Act <http://www.gnb.ca/0062/PDF-acts/t-06.pdf>
1561# says they changed at 00:01 through 2006, and
1562# <http://www.canlii.org/nb/laws/sta/t-6/20030127/whole.html> makes it
1563# clear that this was the case since at least 1993.
1564# For now, assume it started in 1993.
1565
1566# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
1567Rule	Moncton	1933	1935	-	Jun	Sun>=8	1:00	1:00	D
1568Rule	Moncton	1933	1935	-	Sep	Sun>=8	1:00	0	S
1569Rule	Moncton	1936	1938	-	Jun	Sun>=1	1:00	1:00	D
1570Rule	Moncton	1936	1938	-	Sep	Sun>=1	1:00	0	S
1571Rule	Moncton	1939	only	-	May	27	1:00	1:00	D
1572Rule	Moncton	1939	1941	-	Sep	Sat>=21	1:00	0	S
1573Rule	Moncton	1940	only	-	May	19	1:00	1:00	D
1574Rule	Moncton	1941	only	-	May	 4	1:00	1:00	D
1575Rule	Moncton	1946	1972	-	Apr	lastSun	2:00	1:00	D
1576Rule	Moncton	1946	1956	-	Sep	lastSun	2:00	0	S
1577Rule	Moncton	1957	1972	-	Oct	lastSun	2:00	0	S
1578Rule	Moncton	1993	2006	-	Apr	Sun>=1	0:01	1:00	D
1579Rule	Moncton	1993	2006	-	Oct	lastSun	0:01	0	S
1580# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
1581Zone America/Moncton	-4:19:08 -	LMT	1883 Dec  9
1582			-5:00	-	EST	1902 Jun 15
1583			-4:00	Canada	A%sT	1933
1584			-4:00	Moncton	A%sT	1942
1585			-4:00	Canada	A%sT	1946
1586			-4:00	Moncton	A%sT	1973
1587			-4:00	Canada	A%sT	1993
1588			-4:00	Moncton	A%sT	2007
1589			-4:00	Canada	A%sT
1590
1591# Quebec
1592
1593# From Paul Eggert (2020-01-10):
1594# See America/Toronto for most of Quebec, including Montreal.
1595# See America/Halifax for the Îles de la Madeleine and the Listuguj reserve.
1596#
1597# Matthews and Vincent (1998) also write that Quebec east of the -63
1598# meridian is supposed to observe AST, but residents as far east as
1599# Natashquan use EST/EDT, and residents east of Natashquan use AST.
1600# The Quebec department of justice writes in
1601# "The situation in Minganie and Basse-Côte-Nord"
1602# https://www.justice.gouv.qc.ca/en/department/ministre/functions-and-responsabilities/legal-time-in-quebec/the-situation-in-minganie-and-basse-cote-nord/
1603# that the coastal strip from just east of Natashquan to Blanc-Sablon
1604# observes Atlantic standard time all year round.
1605# This common practice was codified into law as of 2007; see Legal Time Act,
1606# CQLR c T-5.1 <http://legisquebec.gouv.qc.ca/en/ShowDoc/cs/T-5.1>.
1607# For lack of better info, guess this practice began around 1970, contra to
1608# Shanks & Pottenger who have this region observing AST/ADT.
1609
1610# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
1611Zone America/Blanc-Sablon -3:48:28 -	LMT	1884
1612			-4:00	Canada	A%sT	1970
1613			-4:00	-	AST
1614
1615# Ontario
1616
1617# From Paul Eggert (2006-07-09):
1618# Shanks & Pottenger write that since 1970 most of Ontario has been like
1619# Toronto.
1620# Thunder Bay skipped DST in 1973.
1621# Many smaller locales did not observe peacetime DST until 1974;
1622# Nipigon (EST) and Rainy River (CST) are the largest that we know of.
1623# Far west Ontario is like Winnipeg; far east Quebec is like Halifax.
1624
1625# From Jeffery Nichols (2020-02-06):
1626# According to the [Shanks] atlas, those western Ontario zones are huge,
1627# covering most of Ontario northwest of Sault Ste Marie and Timmins.
1628# The zones seem to include towns bigger than the ones they're named after,
1629# like Dryden in America/Rainy_River and Wawa (and maybe Attawapiskat) in
1630# America/Nipigon.  I assume it's too much trouble to change the name of the
1631# zone (like when you found out that America/Glace_Bay includes Sydney, Nova
1632# Scotia)....
1633
1634# From Mark Brader (2003-07-26):
1635# [According to the Toronto Star] Orillia, Ontario, adopted DST
1636# effective Saturday, 1912-06-22, 22:00; the article mentions that
1637# Port Arthur (now part of Thunder Bay, Ontario) as well as Moose Jaw
1638# have already done so.  In Orillia DST was to run until Saturday,
1639# 1912-08-31 (no time mentioned), but it was met with considerable
1640# hostility from certain segments of the public, and was revoked after
1641# only two weeks - I copied it as Saturday, 1912-07-07, 22:00, but
1642# presumably that should be -07-06.  (1912-06-19, -07-12; also letters
1643# earlier in June).
1644#
1645# Kenora, Ontario, was to abandon DST on 1914-06-01 (-05-21).
1646#
1647# From Paul Eggert (2017-07-08):
1648# For more on Orillia, see: Daubs K. Bold attempt at daylight saving
1649# time became a comic failure in Orillia. Toronto Star 2017-07-08.
1650# https://www.thestar.com/news/insight/2017/07/08/bold-attempt-at-daylight-saving-time-became-a-comic-failure-in-orillia.html
1651
1652# From Paul Eggert (1997-10-17):
1653# Mark Brader writes that an article in the 1997-10-14 Toronto Star
1654# says that Atikokan, Ontario currently does not observe DST,
1655# but will vote on 11-10 whether to use EST/EDT.
1656# He also writes that the Ontario Time Act (1990, Chapter T.9)
1657# http://www.gov.on.ca/MBS/english/publications/statregs/conttext.html
1658# says that Ontario east of 90W uses EST/EDT, and west of 90W uses CST/CDT.
1659# Officially Atikokan is therefore on CST/CDT, and most likely this report
1660# concerns a non-official time observed as a matter of local practice.
1661#
1662# From Paul Eggert (2000-10-02):
1663# Matthews and Vincent (1998) write that Atikokan, Pickle Lake, and
1664# New Osnaburgh observe CST all year, that Big Trout Lake observes
1665# CST/CDT, and that Upsala and Shebandowan observe EST/EDT, all in
1666# violation of the official Ontario rules.
1667#
1668# From Paul Eggert (2006-07-09):
1669# Chris Walton (2006-07-06) mentioned an article by Stephanie MacLellan in the
1670# 2005-07-21 Chronicle-Journal, which said:
1671#
1672#	The clocks in Atikokan stay set on standard time year-round.
1673#	This means they spend about half the time on central time and
1674#	the other half on eastern time.
1675#
1676#	For the most part, the system works, Mayor Dennis Brown said.
1677#
1678#	"The majority of businesses in Atikokan deal more with Eastern
1679#	Canada, but there are some that deal with Western Canada," he
1680#	said.  "I don't see any changes happening here."
1681#
1682# Walton also writes "Supposedly Pickle Lake and Mishkeegogamang
1683# [New Osnaburgh] follow the same practice."
1684
1685# From Garry McKinnon (2006-07-14) via Chris Walton:
1686# I chatted with a member of my board who has an outstanding memory
1687# and a long history in Atikokan (and in the telecom industry) and he
1688# can say for certain that Atikokan has been practicing the current
1689# time keeping since 1952, at least.
1690
1691# From Paul Eggert (2006-07-17):
1692# Shanks & Pottenger say that Atikokan has agreed with Rainy River
1693# ever since standard time was introduced, but the information from
1694# McKinnon sounds more authoritative.  For now, assume that Atikokan
1695# switched to EST immediately after WWII era daylight saving time
1696# ended.  This matches the old (less-populous) America/Coral_Harbour
1697# entry since our cutoff date of 1970, so we can move
1698# America/Coral_Harbour to the 'backward' file.
1699
1700# From Mark Brader (2010-03-06):
1701#
1702# Currently the database has:
1703#
1704# # Ontario
1705#
1706# # From Paul Eggert (2006-07-09):
1707# # Shanks & Pottenger write that since 1970 most of Ontario has been like
1708# # Toronto.
1709# # Thunder Bay skipped DST in 1973.
1710# # Many smaller locales did not observe peacetime DST until 1974;
1711# # Nipigon (EST) and Rainy River (CST) are the largest that we know of.
1712#
1713# In the (Toronto) Globe and Mail for Saturday, 1955-09-24, in the bottom
1714# right corner of page 1, it says that Toronto will return to standard
1715# time at 2 am Sunday morning (which agrees with the database), and that:
1716#
1717#     The one-hour setback will go into effect throughout most of Ontario,
1718#     except in areas like Windsor which remains on standard time all year.
1719#
1720# Windsor is, of course, a lot larger than Nipigon.
1721#
1722# I only came across this incidentally.  I don't know if Windsor began
1723# observing DST when Detroit did, or in 1974, or on some other date.
1724#
1725# By the way, the article continues by noting that:
1726#
1727#     Some cities in the United States have pushed the deadline back
1728#     three weeks and will change over from daylight saving in October.
1729
1730# From Arthur David Olson (2010-07-17):
1731#
1732# "Standard Time and Time Zones in Canada" appeared in
1733# The Journal of The Royal Astronomical Society of Canada,
1734# volume 26, number 2 (February 1932) and, as of 2010-07-17,
1735# was available at
1736# http://adsabs.harvard.edu/full/1932JRASC..26...49S
1737#
1738# It includes the text below (starting on page 57):
1739#
1740#   A list of the places in Canada using daylight saving time would
1741# require yearly revision. From information kindly furnished by
1742# the provincial governments and by the postmasters in many cities
1743# and towns, it is found that the following places used daylight sav-
1744# ing in 1930. The information for the province of Quebec is definite,
1745# for the other provinces only approximate:
1746#
1747#	Province	Daylight saving time used
1748# Prince Edward Island	Not used.
1749# Nova Scotia		In Halifax only.
1750# New Brunswick		In St. John only.
1751# Quebec		In the following places:
1752#			Montreal	Lachine
1753#			Quebec		Mont-Royal
1754#			Lévis		Iberville
1755#			St. Lambert	Cap de la Madelèine
1756#			Verdun		Loretteville
1757#			Westmount	Richmond
1758#			Outremont	St. Jérôme
1759#			Longueuil	Greenfield Park
1760#			Arvida		Waterloo
1761#			Chambly-Canton	Beaulieu
1762#			Melbourne	La Tuque
1763#			St. Théophile	Buckingham
1764# Ontario		Used generally in the cities and towns along
1765#			the southerly part of the province. Not
1766#			used in the northwesterly part.
1767# Manitoba		Not used.
1768# Saskatchewan		In Regina only.
1769# Alberta		Not used.
1770# British Columbia	Not used.
1771#
1772#   With some exceptions, the use of daylight saving may be said to be limited
1773# to those cities and towns lying between Quebec city and Windsor, Ont.
1774
1775# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
1776Rule	Toronto	1919	only	-	Mar	30	23:30	1:00	D
1777Rule	Toronto	1919	only	-	Oct	26	0:00	0	S
1778Rule	Toronto	1920	only	-	May	 2	2:00	1:00	D
1779Rule	Toronto	1920	only	-	Sep	26	0:00	0	S
1780Rule	Toronto	1921	only	-	May	15	2:00	1:00	D
1781Rule	Toronto	1921	only	-	Sep	15	2:00	0	S
1782Rule	Toronto	1922	1923	-	May	Sun>=8	2:00	1:00	D
1783# Shanks & Pottenger say 1923-09-19; assume it's a typo and that "-16"
1784# was meant.
1785Rule	Toronto	1922	1926	-	Sep	Sun>=15	2:00	0	S
1786Rule	Toronto	1924	1927	-	May	Sun>=1	2:00	1:00	D
1787Rule	Toronto	1927	1937	-	Sep	Sun>=25	2:00	0	S
1788Rule	Toronto	1928	1937	-	Apr	Sun>=25	2:00	1:00	D
1789Rule	Toronto	1938	1940	-	Apr	lastSun	2:00	1:00	D
1790Rule	Toronto	1938	1939	-	Sep	lastSun	2:00	0	S
1791Rule	Toronto	1945	1946	-	Sep	lastSun	2:00	0	S
1792Rule	Toronto	1946	only	-	Apr	lastSun	2:00	1:00	D
1793Rule	Toronto	1947	1949	-	Apr	lastSun	0:00	1:00	D
1794Rule	Toronto	1947	1948	-	Sep	lastSun	0:00	0	S
1795Rule	Toronto	1949	only	-	Nov	lastSun	0:00	0	S
1796Rule	Toronto	1950	1973	-	Apr	lastSun	2:00	1:00	D
1797Rule	Toronto	1950	only	-	Nov	lastSun	2:00	0	S
1798Rule	Toronto	1951	1956	-	Sep	lastSun	2:00	0	S
1799# Shanks & Pottenger say Toronto ended DST a week early in 1971,
1800# namely on 1971-10-24, but Mark Brader wrote (2003-05-31) that this
1801# is wrong, and that he had confirmed it by checking the 1971-10-30
1802# Toronto Star, which said that DST was ending 1971-10-31 as usual.
1803Rule	Toronto	1957	1973	-	Oct	lastSun	2:00	0	S
1804
1805# From Paul Eggert (2003-07-27):
1806# Willett (1914-03) writes (p. 17) "In the Cities of Fort William, and
1807# Port Arthur, Ontario, the principle of the Bill has been in
1808# operation for the past three years, and in the City of Moose Jaw,
1809# Saskatchewan, for one year."
1810
1811# From David Bryan via Tory Tronrud, Director/Curator,
1812# Thunder Bay Museum (2003-11-12):
1813# There is some suggestion, however, that, by-law or not, daylight
1814# savings time was being practiced in Fort William and Port Arthur
1815# before 1909.... [I]n 1910, the line between the Eastern and Central
1816# Time Zones was permanently moved about two hundred miles west to
1817# include the Thunder Bay area....  When Canada adopted daylight
1818# savings time in 1916, Fort William and Port Arthur, having done so
1819# already, did not change their clocks....  During the Second World
1820# War,... [t]he cities agreed to implement DST during the summer
1821# months for the remainder of the war years.
1822
1823# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
1824Zone America/Toronto	-5:17:32 -	LMT	1895
1825			-5:00	Canada	E%sT	1919
1826			-5:00	Toronto	E%sT	1942 Feb  9  2:00s
1827			-5:00	Canada	E%sT	1946
1828			-5:00	Toronto	E%sT	1974
1829			-5:00	Canada	E%sT
1830Zone America/Thunder_Bay -5:57:00 -	LMT	1895
1831			-6:00	-	CST	1910
1832			-5:00	-	EST	1942
1833			-5:00	Canada	E%sT	1970
1834			-5:00	Toronto	E%sT	1973
1835			-5:00	-	EST	1974
1836			-5:00	Canada	E%sT
1837Zone America/Nipigon	-5:53:04 -	LMT	1895
1838			-5:00	Canada	E%sT	1940 Sep 29
1839			-5:00	1:00	EDT	1942 Feb  9  2:00s
1840			-5:00	Canada	E%sT
1841Zone America/Rainy_River -6:18:16 -	LMT	1895
1842			-6:00	Canada	C%sT	1940 Sep 29
1843			-6:00	1:00	CDT	1942 Feb  9  2:00s
1844			-6:00	Canada	C%sT
1845Zone America/Atikokan	-6:06:28 -	LMT	1895
1846			-6:00	Canada	C%sT	1940 Sep 29
1847			-6:00	1:00	CDT	1942 Feb  9  2:00s
1848			-6:00	Canada	C%sT	1945 Sep 30  2:00
1849			-5:00	-	EST
1850
1851
1852# Manitoba
1853
1854# From Rob Douglas (2006-04-06):
1855# the old Manitoba Time Act - as amended by Bill 2, assented to
1856# March 27, 1987 ... said ...
1857# "between two o'clock Central Standard Time in the morning of
1858# the first Sunday of April of each year and two o'clock Central
1859# Standard Time in the morning of the last Sunday of October next
1860# following, one hour in advance of Central Standard Time."...
1861# I believe that the English legislation [of the old time act] had
1862# been assented to (March 22, 1967)....
1863# Also, as far as I can tell, there was no order-in-council varying
1864# the time of Daylight Saving Time for 2005 and so the provisions of
1865# the 1987 version would apply - the changeover was at 2:00 Central
1866# Standard Time (i.e. not until 3:00 Central Daylight Time).
1867
1868# From Paul Eggert (2006-04-10):
1869# Shanks & Pottenger say Manitoba switched at 02:00 (not 02:00s)
1870# starting 1966.  Since 02:00s is clearly correct for 1967 on, assume
1871# it was also 02:00s in 1966.
1872
1873# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
1874Rule	Winn	1916	only	-	Apr	23	0:00	1:00	D
1875Rule	Winn	1916	only	-	Sep	17	0:00	0	S
1876Rule	Winn	1918	only	-	Apr	14	2:00	1:00	D
1877Rule	Winn	1918	only	-	Oct	27	2:00	0	S
1878Rule	Winn	1937	only	-	May	16	2:00	1:00	D
1879Rule	Winn	1937	only	-	Sep	26	2:00	0	S
1880Rule	Winn	1942	only	-	Feb	 9	2:00	1:00	W # War
1881Rule	Winn	1945	only	-	Aug	14	23:00u	1:00	P # Peace
1882Rule	Winn	1945	only	-	Sep	lastSun	2:00	0	S
1883Rule	Winn	1946	only	-	May	12	2:00	1:00	D
1884Rule	Winn	1946	only	-	Oct	13	2:00	0	S
1885Rule	Winn	1947	1949	-	Apr	lastSun	2:00	1:00	D
1886Rule	Winn	1947	1949	-	Sep	lastSun	2:00	0	S
1887Rule	Winn	1950	only	-	May	 1	2:00	1:00	D
1888Rule	Winn	1950	only	-	Sep	30	2:00	0	S
1889Rule	Winn	1951	1960	-	Apr	lastSun	2:00	1:00	D
1890Rule	Winn	1951	1958	-	Sep	lastSun	2:00	0	S
1891Rule	Winn	1959	only	-	Oct	lastSun	2:00	0	S
1892Rule	Winn	1960	only	-	Sep	lastSun	2:00	0	S
1893Rule	Winn	1963	only	-	Apr	lastSun	2:00	1:00	D
1894Rule	Winn	1963	only	-	Sep	22	2:00	0	S
1895Rule	Winn	1966	1986	-	Apr	lastSun	2:00s	1:00	D
1896Rule	Winn	1966	2005	-	Oct	lastSun	2:00s	0	S
1897Rule	Winn	1987	2005	-	Apr	Sun>=1	2:00s	1:00	D
1898# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
1899Zone America/Winnipeg	-6:28:36 -	LMT	1887 Jul 16
1900			-6:00	Winn	C%sT	2006
1901			-6:00	Canada	C%sT
1902
1903
1904# Saskatchewan
1905
1906# From Mark Brader (2003-07-26):
1907# The first actual adoption of DST in Canada was at the municipal
1908# level.  As the [Toronto] Star put it (1912-06-07), "While people
1909# elsewhere have long been talking of legislation to save daylight,
1910# the city of Moose Jaw [Saskatchewan] has acted on its own hook."
1911# DST in Moose Jaw began on Saturday, 1912-06-01 (no time mentioned:
1912# presumably late evening, as below), and would run until "the end of
1913# the summer".  The discrepancy between municipal time and railroad
1914# time was noted.
1915
1916# From Paul Eggert (2003-07-27):
1917# Willett (1914-03) notes that DST "has been in operation ... in the
1918# City of Moose Jaw, Saskatchewan, for one year."
1919
1920# From Paul Eggert (2019-07-25):
1921# Pearce's book says Regina observed DST in 1914-1917.  No dates and times,
1922# unfortunately.  It also says that in 1914 Saskatoon observed DST
1923# from 1 June to 6 July, and that DST was also tried out in Davidson,
1924# Melfort, and Prince Albert.
1925
1926# From Paul Eggert (2006-03-22):
1927# Shanks & Pottenger say that since 1970 this region has mostly been as Regina.
1928# Some western towns (e.g. Swift Current) switched from MST/MDT to CST in 1972.
1929# Other western towns (e.g. Lloydminster) are like Edmonton.
1930# Matthews and Vincent (1998) write that Denare Beach and Creighton
1931# are like Winnipeg, in violation of Saskatchewan law.
1932
1933# From W. Jones (1992-11-06):
1934# The. . .below is based on information I got from our law library, the
1935# provincial archives, and the provincial Community Services department.
1936# A precise history would require digging through newspaper archives, and
1937# since you didn't say what you wanted, I didn't bother.
1938#
1939# Saskatchewan is split by a time zone meridian (105W) and over the years
1940# the boundary became pretty ragged as communities near it reevaluated
1941# their affiliations in one direction or the other.  In 1965 a provincial
1942# referendum favoured legislating common time practices.
1943#
1944# On 15 April 1966 the Time Act (c. T-14, Revised Statutes of
1945# Saskatchewan 1978) was proclaimed, and established that the eastern
1946# part of Saskatchewan would use CST year round, that districts in
1947# northwest Saskatchewan would by default follow CST but could opt to
1948# follow Mountain Time rules (thus 1 hour difference in the winter and
1949# zero in the summer), and that districts in southwest Saskatchewan would
1950# by default follow MT but could opt to follow CST.
1951#
1952# It took a few years for the dust to settle (I know one story of a town
1953# on one time zone having its school in another, such that a mom had to
1954# serve her family lunch in two shifts), but presently it seems that only
1955# a few towns on the border with Alberta (e.g. Lloydminster) follow MT
1956# rules any more; all other districts appear to have used CST year round
1957# since sometime in the 1960s.
1958
1959# From Chris Walton (2006-06-26):
1960# The Saskatchewan time act which was last updated in 1996 is about 30 pages
1961# long and rather painful to read.
1962# http://www.qp.gov.sk.ca/documents/English/Statutes/Statutes/T14.pdf
1963
1964# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
1965Rule	Regina	1918	only	-	Apr	14	2:00	1:00	D
1966Rule	Regina	1918	only	-	Oct	27	2:00	0	S
1967Rule	Regina	1930	1934	-	May	Sun>=1	0:00	1:00	D
1968Rule	Regina	1930	1934	-	Oct	Sun>=1	0:00	0	S
1969Rule	Regina	1937	1941	-	Apr	Sun>=8	0:00	1:00	D
1970Rule	Regina	1937	only	-	Oct	Sun>=8	0:00	0	S
1971Rule	Regina	1938	only	-	Oct	Sun>=1	0:00	0	S
1972Rule	Regina	1939	1941	-	Oct	Sun>=8	0:00	0	S
1973Rule	Regina	1942	only	-	Feb	 9	2:00	1:00	W # War
1974Rule	Regina	1945	only	-	Aug	14	23:00u	1:00	P # Peace
1975Rule	Regina	1945	only	-	Sep	lastSun	2:00	0	S
1976Rule	Regina	1946	only	-	Apr	Sun>=8	2:00	1:00	D
1977Rule	Regina	1946	only	-	Oct	Sun>=8	2:00	0	S
1978Rule	Regina	1947	1957	-	Apr	lastSun	2:00	1:00	D
1979Rule	Regina	1947	1957	-	Sep	lastSun	2:00	0	S
1980Rule	Regina	1959	only	-	Apr	lastSun	2:00	1:00	D
1981Rule	Regina	1959	only	-	Oct	lastSun	2:00	0	S
1982#
1983Rule	Swift	1957	only	-	Apr	lastSun	2:00	1:00	D
1984Rule	Swift	1957	only	-	Oct	lastSun	2:00	0	S
1985Rule	Swift	1959	1961	-	Apr	lastSun	2:00	1:00	D
1986Rule	Swift	1959	only	-	Oct	lastSun	2:00	0	S
1987Rule	Swift	1960	1961	-	Sep	lastSun	2:00	0	S
1988# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
1989Zone America/Regina	-6:58:36 -	LMT	1905 Sep
1990			-7:00	Regina	M%sT	1960 Apr lastSun  2:00
1991			-6:00	-	CST
1992Zone America/Swift_Current -7:11:20 -	LMT	1905 Sep
1993			-7:00	Canada	M%sT	1946 Apr lastSun  2:00
1994			-7:00	Regina	M%sT	1950
1995			-7:00	Swift	M%sT	1972 Apr lastSun  2:00
1996			-6:00	-	CST
1997
1998
1999# Alberta
2000
2001# From Alois Triendl (2019-07-19):
2002# There was no DST in Alberta in 1967... Calgary Herald, 29 April 1967.
2003# 1969, no DST, from Edmonton Journal 18 April 1969
2004#
2005# From Paul Eggert (2019-07-25):
2006# Pearce's book says that Alberta's 1948 Daylight Saving Act required
2007# Mountain Standard Time without DST, and that "anyone who broke that law
2008# could be fined up to $25 and costs".  There seems to be no record of
2009# anybody paying the fine.  The law was not changed until an August 1971
2010# plebiscite reinstituted DST in 1972.  This story is also mentioned in:
2011# Boyer JP. Forcing Choice: The Risky Reward of Referendums. Dundum. 2017.
2012# ISBN 978-1459739123.
2013
2014# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
2015Rule	Edm	1918	1919	-	Apr	Sun>=8	2:00	1:00	D
2016Rule	Edm	1918	only	-	Oct	27	2:00	0	S
2017Rule	Edm	1919	only	-	May	27	2:00	0	S
2018Rule	Edm	1920	1923	-	Apr	lastSun	2:00	1:00	D
2019Rule	Edm	1920	only	-	Oct	lastSun	2:00	0	S
2020Rule	Edm	1921	1923	-	Sep	lastSun	2:00	0	S
2021Rule	Edm	1942	only	-	Feb	 9	2:00	1:00	W # War
2022Rule	Edm	1945	only	-	Aug	14	23:00u	1:00	P # Peace
2023Rule	Edm	1945	only	-	Sep	lastSun	2:00	0	S
2024Rule	Edm	1947	only	-	Apr	lastSun	2:00	1:00	D
2025Rule	Edm	1947	only	-	Sep	lastSun	2:00	0	S
2026Rule	Edm	1972	1986	-	Apr	lastSun	2:00	1:00	D
2027Rule	Edm	1972	2006	-	Oct	lastSun	2:00	0	S
2028# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
2029Zone America/Edmonton	-7:33:52 -	LMT	1906 Sep
2030			-7:00	Edm	M%sT	1987
2031			-7:00	Canada	M%sT
2032
2033
2034# British Columbia
2035
2036# From Paul Eggert (2006-03-22):
2037# Shanks & Pottenger write that since 1970 most of this region has
2038# been like Vancouver.
2039# Dawson Creek uses MST.  Much of east BC is like Edmonton.
2040# Matthews and Vincent (1998) write that Creston is like Dawson Creek.
2041
2042# It seems though that (re: Creston) is not entirely correct:
2043
2044# From Chris Walton (2011-12-01):
2045# There are two areas within the Canadian province of British Columbia
2046# that do not currently observe daylight saving:
2047# a) The Creston Valley (includes the town of Creston and surrounding area)
2048# b) The eastern half of the Peace River Regional District
2049# (includes the cities of Dawson Creek and Fort St. John)
2050
2051# Earlier this year I stumbled across a detailed article about the time
2052# keeping history of Creston; it was written by Tammy Hardwick who is the
2053# manager of the Creston & District Museum. The article was written in May 2009.
2054# http://www.ilovecreston.com/?p=articles&t=spec&ar=260
2055# According to the article, Creston has not changed its clocks since June 1918.
2056# i.e. Creston has been stuck on UT-7 for 93 years.
2057# Dawson Creek, on the other hand, changed its clocks as recently as April 1972.
2058
2059# Unfortunately the exact date for the time change in June 1918 remains
2060# unknown and will be difficult to ascertain.  I e-mailed Tammy a few months
2061# ago to ask if Sunday June 2 was a reasonable guess.  She said it was just
2062# as plausible as any other date (in June).  She also said that after writing
2063# the article she had discovered another time change in 1916; this is the
2064# subject of another article which she wrote in October 2010.
2065# http://www.creston.museum.bc.ca/index.php?module=comments&uop=view_comment&cm+id=56
2066
2067# Here is a summary of the three clock change events in Creston's history:
2068# 1. 1884 or 1885: adoption of Mountain Standard Time (GMT-7)
2069# Exact date unknown
2070# 2. Oct 1916: switch to Pacific Standard Time (GMT-8)
2071# Exact date in October unknown; Sunday October 1 is a reasonable guess.
2072# 3. June 1918: switch to Pacific Daylight Time (GMT-7)
2073# Exact date in June unknown; Sunday June 2 is a reasonable guess.
2074# note 1:
2075# On Oct 27/1918 when daylight saving ended in the rest of Canada,
2076# Creston did not change its clocks.
2077# note 2:
2078# During WWII when the Federal Government legislated a mandatory clock change,
2079# Creston did not oblige.
2080# note 3:
2081# There is no guarantee that Creston will remain on Mountain Standard Time
2082# (UTC-7) forever.
2083# The subject was debated at least once this year by the town Council.
2084# http://www.bclocalnews.com/kootenay_rockies/crestonvalleyadvance/news/116760809.html
2085
2086# During a period WWII, summer time (Daylight saying) was mandatory in Canada.
2087# In Creston, that was handled by shifting the area to PST (-8:00) then applying
2088# summer time to cause the offset to be -7:00, the same as it had been before
2089# the change.  It can be argued that the timezone abbreviation during this
2090# period should be PDT rather than MST, but that doesn't seem important enough
2091# (to anyone) to further complicate the rules.
2092
2093# The transition dates (and times) are guesses.
2094
2095# From Matt Johnson (2015-09-21):
2096# Fort Nelson, BC, Canada will cancel DST this year.  So while previously they
2097# were aligned with America/Vancouver, they're now aligned with
2098# America/Dawson_Creek.
2099# http://www.northernrockies.ca/EN/meta/news/archives/2015/northern-rockies-time-change.html
2100#
2101# From Tim Parenti (2015-09-23):
2102# This requires a new zone for the Northern Rockies Regional Municipality,
2103# America/Fort_Nelson.  The resolution of 2014-12-08 was reached following a
2104# 2014-11-15 poll with nearly 75% support.  Effectively, the municipality has
2105# been on MST (-0700) like Dawson Creek since it advanced its clocks on
2106# 2015-03-08.
2107#
2108# From Paul Eggert (2019-07-25):
2109# Shanks says Fort Nelson did not observe DST in 1946, unlike Vancouver.
2110# Alois Triendl confirmed this on 07-22, citing the 1946-04-27 Vancouver Daily
2111# Province.  He also cited the 1946-09-28 Victoria Daily Times, which said
2112# that Vancouver, Victoria, etc. "change at midnight Saturday"; for now,
2113# guess they meant 02:00 Sunday since 02:00 was common practice in Vancouver.
2114#
2115# Early Vancouver, Volume Four, by Major J.S. Matthews, V.D., 2011 edition
2116# says that a 1922 plebiscite adopted DST, but a 1923 plebiscite rejected it.
2117# http://former.vancouver.ca/ctyclerk/archives/digitized/EarlyVan/SearchEarlyVan/Vol4pdf/MatthewsEarlyVancouverVol4_DaylightSavings.pdf
2118# A catalog entry for a newspaper clipping seems to indicate that Vancouver
2119# observed DST in 1941 from 07-07 through 09-27; see
2120# https://searcharchives.vancouver.ca/daylight-saving-1918-starts-again-july-7-1941-start-d-s-sept-27-end-of-d-s-1941
2121# We have no further details, so omit them for now.
2122
2123# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
2124Rule	Vanc	1918	only	-	Apr	14	2:00	1:00	D
2125Rule	Vanc	1918	only	-	Oct	27	2:00	0	S
2126Rule	Vanc	1942	only	-	Feb	 9	2:00	1:00	W # War
2127Rule	Vanc	1945	only	-	Aug	14	23:00u	1:00	P # Peace
2128Rule	Vanc	1945	only	-	Sep	30	2:00	0	S
2129Rule	Vanc	1946	1986	-	Apr	lastSun	2:00	1:00	D
2130Rule	Vanc	1946	only	-	Sep	29	2:00	0	S
2131Rule	Vanc	1947	1961	-	Sep	lastSun	2:00	0	S
2132Rule	Vanc	1962	2006	-	Oct	lastSun	2:00	0	S
2133# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
2134Zone America/Vancouver	-8:12:28 -	LMT	1884
2135			-8:00	Vanc	P%sT	1987
2136			-8:00	Canada	P%sT
2137Zone America/Dawson_Creek -8:00:56 -	LMT	1884
2138			-8:00	Canada	P%sT	1947
2139			-8:00	Vanc	P%sT	1972 Aug 30  2:00
2140			-7:00	-	MST
2141Zone America/Fort_Nelson	-8:10:47 -	LMT	1884
2142			-8:00	Vanc	P%sT	1946
2143			-8:00	-	PST	1947
2144			-8:00	Vanc	P%sT	1987
2145			-8:00	Canada	P%sT	2015 Mar  8  2:00
2146			-7:00	-	MST
2147Zone America/Creston	-7:46:04 -	LMT	1884
2148			-7:00	-	MST	1916 Oct 1
2149			-8:00	-	PST	1918 Jun 2
2150			-7:00	-	MST
2151
2152# Northwest Territories, Nunavut, Yukon
2153
2154# From Paul Eggert (2006-03-22):
2155# Dawson switched to PST in 1973.  Inuvik switched to MST in 1979.
2156# Mathew Englander (1996-10-07) gives the following refs:
2157#	* 1967. Paragraph 28(34)(g) of the Interpretation Act, S.C. 1967-68,
2158#	c. 7 defines Yukon standard time as UTC-9....
2159#	see Interpretation Act, R.S.C. 1985, c. I-21, s. 35(1).
2160#	[https://www.canlii.org/en/ca/laws/stat/rsc-1985-c-i-21/latest/rsc-1985-c-i-21.html]
2161#	* C.O. 1973/214 switched Yukon to PST on 1973-10-28 00:00.
2162#	* O.I.C. 1980/02 established DST.
2163#	* O.I.C. 1987/056 changed DST to Apr firstSun 2:00 to Oct lastSun 2:00.
2164
2165# From Brian Inglis (2015-04-14):
2166#
2167# I tried to trace the history of Yukon time and found the following
2168# regulations, giving the reference title and URL if found, regulation name,
2169# and relevant quote if available.  Each regulation specifically revokes its
2170# predecessor.  The final reference is to the current Interpretation Act
2171# authorizing and resulting from these regulatory changes.
2172#
2173# Only recent regulations were retrievable via Yukon government site search or
2174# index, and only some via Canadian legal sources.  Other sources used include
2175# articles titled "Standard Time and Time Zones in Canada" from JRASC via ADS
2176# Abstracts, cited by ADO for 1932 ..., and updated versions from 1958 and
2177# 1970 quoted below; each article includes current extracts from provincial
2178# and territorial ST and DST regulations at the end, summaries and details of
2179# standard times and daylight saving time at many locations across Canada,
2180# with time zone maps, tables and calculations for Canadian Sunrise, Sunset,
2181# and LMST; they also cover many countries and global locations, with a chart
2182# and table showing current Universal Time offsets, and may be useful as
2183# another source of information for 1970 and earlier.
2184#
2185# * Standard Time and Time Zones in Canada; Smith, C.C.; JRASC, Vol. 26,
2186#   pp.49-77; February 1932; SAO/NASA Astrophysics Data System (ADS)
2187#   http://adsabs.harvard.edu/abs/1932JRASC..26...49S from p.75:
2188#   Yukon Interpretation Ordinance
2189#   Yukon standard time is the local mean time at the one hundred and
2190#   thirty-fifth meridian.
2191#
2192# * Standard Time and Time Zones in Canada; Smith, C.C.; Thomson, Malcolm M.;
2193#   JRASC, Vol. 52, pp.193-223; October 1958; SAO/NASA Astrophysics Data System
2194#   (ADS) http://adsabs.harvard.edu/abs/1958JRASC..52..193S from pp.220-1:
2195#   Yukon Interpretation Ordinance, 1955, Chap. 16.
2196#
2197#     (1) Subject to this section, standard time shall be reckoned as nine
2198#     hours behind Greenwich Time and called Yukon Standard Time.
2199#
2200#     (2) Notwithstanding subsection (1), the Commissioner may make regulations
2201#     varying the manner of reckoning standard time.
2202#
2203# * Yukon Territory Commissioner's Order 1966-20 Interpretation Ordinance
2204#   [no online source found]
2205#
2206# * Standard Time and Time Zones in Canada; Thomson, Malcolm M.; JRASC,
2207#   Vol. 64, pp.129-162; June 1970; SAO/NASA Astrophysics Data System (ADS)
2208#   http://adsabs.harvard.edu/abs/1970JRASC..64..129T from p.156: Yukon
2209#   Territory Commissioner's Order 1967-59 Interpretation Ordinance ...
2210#
2211#     1. Commissioner's Order 1966-20 dated at Whitehorse in the Yukon
2212#     Territory on 27th January, 1966, is hereby revoked.
2213#
2214#     2. Yukon (East) Standard Time as defined by section 36 of the
2215#     Interpretation Ordinance from and after mid-night on the 28th day of May,
2216#     1967 shall be reckoned in the same manner as Pacific Standard Time, that
2217#     is to say, eight hours behind Greenwich Time in the area of the Yukon
2218#     Territory lying east of the 138th degree longitude west.
2219#
2220#     3. In the remainder of the Territory, lying west of the 138th degree
2221#     longitude west, Yukon (West) Standard Time shall be reckoned as nine
2222#     hours behind Greenwich Time.
2223#
2224# * Yukon Standard Time defined as Pacific Standard Time, YCO 1973/214
2225#   https://www.canlii.org/en/yk/laws/regu/yco-1973-214/latest/yco-1973-214.html
2226#   C.O. 1973/214 INTERPRETATION ACT ...
2227#
2228#     1. Effective October 28, 1973 Commissioner's Order 1967/59 is hereby
2229#     revoked.
2230#
2231#     2. Yukon Standard Time as defined by section 36 of the Interpretation
2232#     Act from and after midnight on the twenty-eighth day of October, 1973
2233#     shall be reckoned in the same manner as Pacific Standard Time, that is
2234#     to say eight hours behind Greenwich Time.
2235#
2236# * O.I.C. 1980/02 INTERPRETATION ACT
2237#   [no online source found]
2238#
2239# * Yukon Daylight Saving Time, YOIC 1987/56
2240#   https://www.canlii.org/en/yk/laws/regu/yoic-1987-56/latest/yoic-1987-56.html
2241#   O.I.C. 1987/056 INTERPRETATION ACT ...
2242#
2243#   In every year between
2244#     (a) two o'clock in the morning in the first Sunday in April, and
2245#     (b) two o'clock in the morning in the last Sunday in October,
2246#   Standard Time shall be reckoned as seven hours behind Greenwich Time and
2247#   called Yukon Daylight Saving Time.
2248#   ...
2249#   Dated ... 9th day of March, A.D., 1987.
2250#
2251# * Yukon Daylight Saving Time 2006, YOIC 2006/127
2252#   https://www.canlii.org/en/yk/laws/regu/yoic-2006-127/latest/yoic-2006-127.html
2253#   O.I.C. 2006/127 INTERPRETATION ACT ...
2254#
2255#     1. In Yukon each year the time for general purposes shall be 7 hours
2256#     behind Greenwich mean time during the period commencing at two o'clock
2257#     in the forenoon on the second Sunday of March and ending at two o'clock
2258#     in the forenoon on the first Sunday of November and shall be called
2259#     Yukon Daylight Saving Time.
2260#
2261#     2. Order-in-Council 1987/56 is revoked.
2262#
2263#     3. This order comes into force January 1, 2007.
2264#
2265# * Interpretation Act, RSY 2002, c 125
2266# https://www.canlii.org/en/yk/laws/stat/rsy-2002-c-125/latest/rsy-2002-c-125.html
2267
2268# From Rives McDow (1999-09-04):
2269# Nunavut ... moved ... to incorporate the whole territory into one time zone.
2270# Nunavut moves to single time zone Oct. 31
2271# http://www.nunatsiaq.com/nunavut/nvt90903_13.html
2272#
2273# From Antoine Leca (1999-09-06):
2274# We then need to create a new timezone for the Kitikmeot region of Nunavut
2275# to differentiate it from the Yellowknife region.
2276
2277# From Paul Eggert (1999-09-20):
2278# Basic Facts: The New Territory
2279# http://www.nunavut.com/basicfacts/english/basicfacts_1territory.html
2280# (1999) reports that Pangnirtung operates on eastern time,
2281# and that Coral Harbour does not observe DST.  We don't know when
2282# Pangnirtung switched to eastern time; we'll guess 1995.
2283
2284# From Rives McDow (1999-11-08):
2285# On October 31, when the rest of Nunavut went to Central time,
2286# Pangnirtung wobbled.  Here is the result of their wobble:
2287#
2288# The following businesses and organizations in Pangnirtung use Central Time:
2289#
2290#	First Air, Power Corp, Nunavut Construction, Health Center, RCMP,
2291#	Eastern Arctic National Parks, A & D Specialist
2292#
2293# The following businesses and organizations in Pangnirtung use Eastern Time:
2294#
2295#	Hamlet office, All other businesses, Both schools, Airport operator
2296#
2297# This has made for an interesting situation there, which warranted the news.
2298# No one there that I spoke with seems concerned, or has plans to
2299# change the local methods of keeping time, as it evidently does not
2300# really interfere with any activities or make things difficult locally.
2301# They plan to celebrate New Year's turn-over twice, one hour apart,
2302# so it appears that the situation will last at least that long.
2303# The Nunavut Intergovernmental Affairs hopes that they will "come to
2304# their senses", but the locals evidently don't see any problem with
2305# the current state of affairs.
2306
2307# From Michaela Rodrigue, writing in the
2308# Nunatsiaq News (1999-11-19):
2309# http://www.nunatsiaqonline.ca/archives/nunavut991130/nvt91119_17.html
2310# Clyde River, Pangnirtung and Sanikiluaq now operate with two time zones,
2311# central - or Nunavut time - for government offices, and eastern time
2312# for municipal offices and schools....  Igloolik [was similar but then]
2313# made the switch to central time on Saturday, Nov. 6.
2314
2315# From Paul Eggert (2000-10-02):
2316# Matthews and Vincent (1998) say the following, but we lack histories
2317# for these potential new Zones.
2318#
2319# The Canadian Forces station at Alert uses Eastern Time while the
2320# handful of residents at the Eureka weather station [in the Central
2321# zone] skip daylight savings.  Baffin Island, which is crossed by the
2322# Central, Eastern and Atlantic Time zones only uses Eastern Time.
2323# Gjoa Haven, Taloyoak and Pelly Bay all use Mountain instead of
2324# Central Time and Southampton Island [in the Central zone] is not
2325# required to use daylight savings.
2326
2327# From <http://www.nunatsiaqonline.ca/archives/nunavut001130/nvt21110_02.html>
2328# Nunavut now has two time zones (2000-11-10):
2329# The Nunavut government would allow its employees in Kugluktuk and
2330# Cambridge Bay to operate on central time year-round, putting them
2331# one hour behind the rest of Nunavut for six months during the winter.
2332# At the end of October the two communities had rebelled against
2333# Nunavut's unified time zone, refusing to shift to eastern time with
2334# the rest of the territory for the winter.  Cambridge Bay remained on
2335# central time, while Kugluktuk, even farther west, reverted to
2336# mountain time, which they had used before the advent of Nunavut's
2337# unified time zone in 1999.
2338#
2339# From Rives McDow (2001-01-20), quoting the Nunavut government:
2340# The preceding decision came into effect at midnight, Saturday Nov 4, 2000.
2341
2342# From Paul Eggert (2000-12-04):
2343# Let's just keep track of the official times for now.
2344
2345# From Rives McDow (2001-03-07):
2346# The premier of Nunavut has issued a ministerial statement advising
2347# that effective 2001-04-01, the territory of Nunavut will revert
2348# back to three time zones (mountain, central, and eastern).  Of the
2349# cities in Nunavut, Coral Harbor is the only one that I know of that
2350# has said it will not observe dst, staying on EST year round.  I'm
2351# checking for more info, and will get back to you if I come up with
2352# more.
2353# [Also see <http://www.nunatsiaq.com/nunavut/nvt10309_06.html> (2001-03-09).]
2354
2355# From Gwillim Law (2005-05-21):
2356# According to ...
2357# http://www.canadiangeographic.ca/Magazine/SO98/geomap.asp
2358# (from a 1998 Canadian Geographic article), the de facto and de jure time
2359# for Southampton Island (at the north end of Hudson Bay) is UTC-5 all year
2360# round.  Using Google, it's easy to find other websites that confirm this.
2361# I wasn't able to find how far back this time regimen goes, but since it
2362# predates the creation of Nunavut, it probably goes back many years....
2363# The Inuktitut name of Coral Harbour is Sallit, but it's rarely used.
2364#
2365# From Paul Eggert (2014-10-17):
2366# For lack of better information, assume that Southampton Island observed
2367# daylight saving only during wartime.  Gwillim Law's email also
2368# mentioned maps now maintained by National Research Council Canada;
2369# see above for an up-to-date link.
2370
2371# From Chris Walton (2007-03-01):
2372# ... the community of Resolute (located on Cornwallis Island in
2373# Nunavut) moved from Central Time to Eastern Time last November.
2374# Basically the community did not change its clocks at the end of
2375# daylight saving....
2376# http://www.nnsl.com/frames/newspapers/2006-11/nov13_06none.html
2377
2378# From Chris Walton (2011-03-21):
2379# Back in 2007 I initiated the creation of a new "zone file" for Resolute
2380# Bay. Resolute Bay is a small community located about 900km north of
2381# the Arctic Circle. The zone file was required because Resolute Bay had
2382# decided to use UTC-5 instead of UTC-6 for the winter of 2006-2007.
2383#
2384# According to new information which I received last week, Resolute Bay
2385# went back to using UTC-6 in the winter of 2007-2008...
2386#
2387# On March 11/2007 most of Canada went onto daylight saving. On March
2388# 14/2007 I phoned the Resolute Bay hamlet office to do a "time check." I
2389# talked to somebody that was both knowledgeable and helpful. I was able
2390# to confirm that Resolute Bay was still operating on UTC-5. It was
2391# explained to me that Resolute Bay had been on the Eastern Time zone
2392# (EST) in the winter, and was now back on the Central Time zone (CDT).
2393# i.e. the time zone had changed twice in the last year but the clocks
2394# had not moved. The residents had to know which time zone they were in
2395# so they could follow the correct TV schedule...
2396#
2397# On Nov 02/2008 most of Canada went onto standard time. On Nov 03/2008 I
2398# phoned the Resolute Bay hamlet office...[D]ue to the challenging nature
2399# of the phone call, I decided to seek out an alternate source of
2400# information. I found an e-mail address for somebody by the name of
2401# Stephanie Adams whose job was listed as "Inns North Support Officer for
2402# Arctic Co-operatives." I was under the impression that Stephanie lived
2403# and worked in Resolute Bay...
2404#
2405# On March 14/2011 I phoned the hamlet office again. I was told that
2406# Resolute Bay had been using Central Standard Time over the winter of
2407# 2010-2011 and that the clocks had therefore been moved one hour ahead
2408# on March 13/2011. The person I talked to was aware that Resolute Bay
2409# had previously experimented with Eastern Standard Time but he could not
2410# tell me when the practice had stopped.
2411#
2412# On March 17/2011 I searched the Web to find an e-mail address of
2413# somebody that might be able to tell me exactly when Resolute Bay went
2414# off Eastern Standard Time. I stumbled on the name "Aziz Kheraj." Aziz
2415# used to be the mayor of Resolute Bay and he apparently owns half the
2416# businesses including "South Camp Inn." This website has some info on
2417# Aziz:
2418# http://www.uphere.ca/node/493
2419#
2420# I sent Aziz an e-mail asking when Resolute Bay had stopped using
2421# Eastern Standard Time.
2422#
2423# Aziz responded quickly with this: "hi, The time was not changed for the
2424# 1 year only, the following year, the community went back to the old way
2425# of "spring ahead-fall behind" currently we are zulu plus 5 hrs and in
2426# the winter Zulu plus 6 hrs"
2427#
2428# This of course conflicted with everything I had ascertained in November 2008.
2429#
2430# I sent Aziz a copy of my 2008 e-mail exchange with Stephanie. Aziz
2431# responded with this: "Hi, Stephanie lives in Winnipeg. I live here, You
2432# may want to check with the weather office in Resolute Bay or do a
2433# search on the weather through Env. Canada. web site"
2434#
2435# If I had realized the Stephanie did not live in Resolute Bay I would
2436# never have contacted her.  I now believe that all the information I
2437# obtained in November 2008 should be ignored...
2438# I apologize for reporting incorrect information in 2008.
2439
2440# From Tim Parenti (2020-03-05):
2441# The government of Yukon announced [yesterday] the cessation of seasonal time
2442# changes.  "After clocks are pushed ahead one hour on March 8, the territory
2443# will remain on [UTC-07].  ... [The government] found 93 per cent of
2444# respondents wanted to end seasonal time changes and, of that group, 70 per
2445# cent wanted 'permanent Pacific Daylight Saving Time.'"
2446# https://www.cbc.ca/news/canada/north/yukon-end-daylight-saving-time-1.5486358
2447#
2448# Although the government press release prefers PDT, we prefer MST for
2449# consistency with nearby Dawson Creek, Creston, and Fort Nelson.
2450# https://yukon.ca/en/news/yukon-end-seasonal-time-change
2451
2452# From Andrew G. Smith (2020-09-24):
2453# Yukon has completed its regulatory change to be on UTC -7 year-round....
2454# http://www.gov.yk.ca/legislation/regs/oic2020_125.pdf
2455# What we have done is re-defined Yukon Standard Time, as we are
2456# authorized to do under section 33 of our Interpretation Act:
2457# http://www.gov.yk.ca/legislation/acts/interpretation_c.pdf
2458#
2459# From Paul Eggert (2020-09-24):
2460# tzdb uses the obsolete YST abbreviation for standard time in Yukon through
2461# about 1970, and uses PST for standard time in Yukon since then.  Consistent
2462# with that, use MST for -07, the new standard time in Yukon effective Nov. 1.
2463
2464# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
2465Rule	NT_YK	1918	only	-	Apr	14	2:00	1:00	D
2466Rule	NT_YK	1918	only	-	Oct	27	2:00	0	S
2467Rule	NT_YK	1919	only	-	May	25	2:00	1:00	D
2468Rule	NT_YK	1919	only	-	Nov	 1	0:00	0	S
2469Rule	NT_YK	1942	only	-	Feb	 9	2:00	1:00	W # War
2470Rule	NT_YK	1945	only	-	Aug	14	23:00u	1:00	P # Peace
2471Rule	NT_YK	1945	only	-	Sep	30	2:00	0	S
2472Rule	NT_YK	1965	only	-	Apr	lastSun	0:00	2:00	DD
2473Rule	NT_YK	1965	only	-	Oct	lastSun	2:00	0	S
2474Rule	NT_YK	1980	1986	-	Apr	lastSun	2:00	1:00	D
2475Rule	NT_YK	1980	2006	-	Oct	lastSun	2:00	0	S
2476Rule	NT_YK	1987	2006	-	Apr	Sun>=1	2:00	1:00	D
2477# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
2478# aka Panniqtuuq
2479Zone America/Pangnirtung 0	-	-00	1921 # trading post est.
2480			-4:00	NT_YK	A%sT	1995 Apr Sun>=1  2:00
2481			-5:00	Canada	E%sT	1999 Oct 31  2:00
2482			-6:00	Canada	C%sT	2000 Oct 29  2:00
2483			-5:00	Canada	E%sT
2484# formerly Frobisher Bay
2485Zone America/Iqaluit	0	-	-00	1942 Aug # Frobisher Bay est.
2486			-5:00	NT_YK	E%sT	1999 Oct 31  2:00
2487			-6:00	Canada	C%sT	2000 Oct 29  2:00
2488			-5:00	Canada	E%sT
2489# aka Qausuittuq
2490Zone America/Resolute	0	-	-00	1947 Aug 31 # Resolute founded
2491			-6:00	NT_YK	C%sT	2000 Oct 29  2:00
2492			-5:00	-	EST	2001 Apr  1  3:00
2493			-6:00	Canada	C%sT	2006 Oct 29  2:00
2494			-5:00	-	EST	2007 Mar 11  3:00
2495			-6:00	Canada	C%sT
2496# aka Kangiqiniq
2497Zone America/Rankin_Inlet 0	-	-00	1957 # Rankin Inlet founded
2498			-6:00	NT_YK	C%sT	2000 Oct 29  2:00
2499			-5:00	-	EST	2001 Apr  1  3:00
2500			-6:00	Canada	C%sT
2501# aka Iqaluktuuttiaq
2502Zone America/Cambridge_Bay 0	-	-00	1920 # trading post est.?
2503			-7:00	NT_YK	M%sT	1999 Oct 31  2:00
2504			-6:00	Canada	C%sT	2000 Oct 29  2:00
2505			-5:00	-	EST	2000 Nov  5  0:00
2506			-6:00	-	CST	2001 Apr  1  3:00
2507			-7:00	Canada	M%sT
2508Zone America/Yellowknife 0	-	-00	1935 # Yellowknife founded?
2509			-7:00	NT_YK	M%sT	1980
2510			-7:00	Canada	M%sT
2511Zone America/Inuvik	0	-	-00	1953 # Inuvik founded
2512			-8:00	NT_YK	P%sT	1979 Apr lastSun  2:00
2513			-7:00	NT_YK	M%sT	1980
2514			-7:00	Canada	M%sT
2515Zone America/Whitehorse	-9:00:12 -	LMT	1900 Aug 20
2516			-9:00	NT_YK	Y%sT	1967 May 28  0:00
2517			-8:00	NT_YK	P%sT	1980
2518			-8:00	Canada	P%sT	2020 Nov  1
2519			-7:00	-	MST
2520Zone America/Dawson	-9:17:40 -	LMT	1900 Aug 20
2521			-9:00	NT_YK	Y%sT	1973 Oct 28  0:00
2522			-8:00	NT_YK	P%sT	1980
2523			-8:00	Canada	P%sT	2020 Nov  1
2524			-7:00	-	MST
2525
2526
2527###############################################################################
2528
2529# Mexico
2530
2531# From Paul Eggert (2014-12-07):
2532# The Investigation and Analysis Service of the
2533# Mexican Library of Congress (MLoC) has published a
2534# history of Mexican local time (in Spanish)
2535# http://www.diputados.gob.mx/bibliot/publica/inveyana/polisoc/horver/index.htm
2536#
2537# Here are the discrepancies between Shanks & Pottenger (S&P) and the MLoC.
2538# (In all cases we go with the MLoC.)
2539# S&P report that Baja was at -8:00 in 1922/1923.
2540# S&P say the 1930 transition in Baja was 1930-11-16.
2541# S&P report no DST during summer 1931.
2542# S&P report a transition at 1932-03-30 23:00, not 1932-04-01.
2543
2544# From Gwillim Law (2001-02-20):
2545# There are some other discrepancies between the Decrees page and the
2546# tz database.  I think they can best be explained by supposing that
2547# the researchers who prepared the Decrees page failed to find some of
2548# the relevant documents.
2549
2550# From Alan Perry (1996-02-15):
2551# A guy from our Mexico subsidiary finally found the Presidential Decree
2552# outlining the timezone changes in Mexico.
2553#
2554# ------------- Begin Forwarded Message -------------
2555#
2556# I finally got my hands on the Official Presidential Decree that sets up the
2557# rules for the DST changes. The rules are:
2558#
2559# 1. The country is divided in 3 timezones:
2560#    - Baja California Norte (the Mexico/BajaNorte TZ)
2561#    - Baja California Sur, Nayarit, Sinaloa and Sonora (the Mexico/BajaSur TZ)
2562#    - The rest of the country (the Mexico/General TZ)
2563#
2564# 2. From the first Sunday in April at 2:00 AM to the last Sunday in October
2565#    at 2:00 AM, the times in each zone are as follows:
2566#    BajaNorte: GMT+7
2567#    BajaSur:   GMT+6
2568#    General:   GMT+5
2569#
2570# 3. The rest of the year, the times are as follows:
2571#    BajaNorte: GMT+8
2572#    BajaSur:   GMT+7
2573#    General:   GMT+6
2574#
2575# The Decree was published in Mexico's Official Newspaper on January 4th.
2576#
2577# -------------- End Forwarded Message --------------
2578# From Paul Eggert (1996-06-12):
2579# For an English translation of the decree, see
2580# "Diario Oficial: Time Zone Changeover" (1996-01-04).
2581# http://mexico-travel.com/extra/timezone_eng.html
2582
2583# From Rives McDow (1998-10-08):
2584# The State of Quintana Roo has reverted back to central STD and DST times
2585# (i.e. UTC -0600 and -0500 as of 1998-08-02).
2586
2587# From Rives McDow (2000-01-10):
2588# Effective April 4, 1999 at 2:00 AM local time, Sonora changed to the time
2589# zone 5 hours from the International Date Line, and will not observe daylight
2590# savings time so as to stay on the same time zone as the southern part of
2591# Arizona year round.
2592
2593# From Jesper Nørgaard, translating
2594# <http://www.reforma.com/nacional/articulo/064327/> (2001-01-17):
2595# In Oaxaca, the 55.000 teachers from the Section 22 of the National
2596# Syndicate of Education Workers, refuse to apply daylight saving each
2597# year, so that the more than 10,000 schools work at normal hour the
2598# whole year.
2599
2600# From Gwillim Law (2001-01-19):
2601# <http://www.reforma.com/negocios_y_dinero/articulo/064481/> ... says
2602# (translated):...
2603# January 17, 2000 - The Energy Secretary, Ernesto Martens, announced
2604# that Summer Time will be reduced from seven to five months, starting
2605# this year....
2606# http://www.publico.com.mx/scripts/texto3.asp?action=pagina&pag=21&pos=p&secc=naci&date=01/17/2001
2607# [translated], says "summer time will ... take effect on the first Sunday
2608# in May, and end on the last Sunday of September.
2609
2610# From Arthur David Olson (2001-01-25):
2611# The 2001-01-24 traditional Washington Post contained the page one
2612# story "Timely Issue Divides Mexicans."...
2613# http://www.washingtonpost.com/wp-dyn/articles/A37383-2001Jan23.html
2614# ... Mexico City Mayor López Obrador "...is threatening to keep
2615# Mexico City and its 20 million residents on a different time than
2616# the rest of the country..." In particular, López Obrador would abolish
2617# observation of Daylight Saving Time.
2618
2619# Official statute published by the Energy Department
2620# http://www.conae.gob.mx/ahorro/decretohorver2001.html#decre
2621# (2001-02-01) shows Baja and Chihauhua as still using US DST rules,
2622# and Sonora with no DST.  This was reported by Jesper Nørgaard (2001-02-03).
2623
2624# From Paul Eggert (2001-03-03):
2625#
2626# https://www.latimes.com/archives/la-xpm-2001-mar-03-mn-32561-story.html
2627# James F. Smith writes in today's LA Times
2628# * Sonora will continue to observe standard time.
2629# * Last week Mexico City's mayor Andrés Manuel López Obrador decreed that
2630#   the Federal District will not adopt DST.
2631# * 4 of 16 district leaders announced they'll ignore the decree.
2632# * The decree does not affect federal-controlled facilities including
2633#   the airport, banks, hospitals, and schools.
2634#
2635# For now we'll assume that the Federal District will bow to federal rules.
2636
2637# From Jesper Nørgaard (2001-04-01):
2638# I found some references to the Mexican application of daylight
2639# saving, which modifies what I had already sent you, stating earlier
2640# that a number of northern Mexican states would go on daylight
2641# saving. The modification reverts this to only cover Baja California
2642# (Norte), while all other states (except Sonora, who has no daylight
2643# saving all year) will follow the original decree of president
2644# Vicente Fox, starting daylight saving May 6, 2001 and ending
2645# September 30, 2001.
2646# References: "Diario de Monterrey" <http://www.diariodemonterrey.com/index.asp>
2647# Palabra <http://palabra.infosel.com/010331/primera/ppri3101.pdf> (2001-03-31)
2648
2649# From Reuters (2001-09-04):
2650# Mexico's Supreme Court on Tuesday declared that daylight savings was
2651# unconstitutional in Mexico City, creating the possibility the
2652# capital will be in a different time zone from the rest of the nation
2653# next year....  The Supreme Court's ruling takes effect at 2:00
2654# a.m. (0800 GMT) on Sept. 30, when Mexico is scheduled to revert to
2655# standard time. "This is so residents of the Federal District are not
2656# subject to unexpected time changes," a statement from the court said.
2657
2658# From Jesper Nørgaard Welen (2002-03-12):
2659# ... consulting my local grocery store(!) and my coworkers, they all insisted
2660# that a new decision had been made to reinstate US style DST in Mexico....
2661# http://www.conae.gob.mx/ahorro/horaver2001_m1_2002.html (2002-02-20)
2662# confirms this.  Sonora as usual is the only state where DST is not applied.
2663
2664# From Steffen Thorsen (2009-12-28):
2665#
2666# Steffen Thorsen wrote:
2667# > Mexico's House of Representatives has approved a proposal for northern
2668# > Mexico's border cities to share the same daylight saving schedule as
2669# > the United States.
2670# Now this has passed both the Congress and the Senate, so starting from
2671# 2010, some border regions will be the same:
2672# http://www.signonsandiego.com/news/2009/dec/28/clocks-will-match-both-sides-border/
2673# http://www.elmananarey.com/diario/noticia/nacional/noticias/empatan_horario_de_frontera_con_eu/621939
2674# (Spanish)
2675#
2676# Could not find the new law text, but the proposed law text changes are here:
2677# http://gaceta.diputados.gob.mx/Gaceta/61/2009/dic/20091210-V.pdf
2678# (Gaceta Parlamentaria)
2679#
2680# There is also a list of the votes here:
2681# http://gaceta.diputados.gob.mx/Gaceta/61/2009/dic/V2-101209.html
2682#
2683# Our page:
2684# https://www.timeanddate.com/news/time/north-mexico-dst-change.html
2685
2686# From Arthur David Olson (2010-01-20):
2687# The page
2688# http://dof.gob.mx/nota_detalle.php?codigo=5127480&fecha=06/01/2010
2689# includes this text:
2690# En los municipios fronterizos de Tijuana y Mexicali en Baja California;
2691# Juárez y Ojinaga en Chihuahua; Acuña y Piedras Negras en Coahuila;
2692# Anáhuac en Nuevo León; y Nuevo Laredo, Reynosa y Matamoros en
2693# Tamaulipas, la aplicación de este horario estacional surtirá efecto
2694# desde las dos horas del segundo domingo de marzo y concluirá a las dos
2695# horas del primer domingo de noviembre.
2696# En los municipios fronterizos que se encuentren ubicados en la franja
2697# fronteriza norte en el territorio comprendido entre la línea
2698# internacional y la línea paralela ubicada a una distancia de veinte
2699# kilómetros, así como la Ciudad de Ensenada, Baja California, hacia el
2700# interior del país, la aplicación de este horario estacional surtirá
2701# efecto desde las dos horas del segundo domingo de marzo y concluirá a
2702# las dos horas del primer domingo de noviembre.
2703
2704# From Steffen Thorsen (2014-12-08), translated by Gwillim Law:
2705# The Mexican state of Quintana Roo will likely change to EST in 2015.
2706#
2707# http://www.unioncancun.mx/articulo/2014/12/04/medio-ambiente/congreso-aprueba-una-hora-mas-de-sol-en-qroo
2708# "With this change, the time conflict that has existed between the municipios
2709# of Quintana Roo and the municipio of Felipe Carrillo Puerto may come to an
2710# end. The latter declared itself in rebellion 15 years ago when a time change
2711# was initiated in Mexico, and since then it has refused to change its time
2712# zone along with the rest of the country."
2713#
2714# From Steffen Thorsen (2015-01-14), translated by Gwillim Law:
2715# http://sipse.com/novedades/confirman-aplicacion-de-nueva-zona-horaria-para-quintana-roo-132331.html
2716# "...the new time zone will come into effect at two o'clock on the first Sunday
2717# of February, when we will have to advance the clock one hour from its current
2718# time..."
2719# Also, the new zone will not use DST.
2720#
2721# From Carlos Raúl Perasso (2015-02-02):
2722# The decree that modifies the Mexican Hour System Law has finally
2723# been published at the Diario Oficial de la Federación
2724# http://www.dof.gob.mx/nota_detalle.php?codigo=5380123&fecha=31/01/2015
2725# It establishes 5 zones for Mexico:
2726# 1- Zona Centro (Central Zone): Corresponds to longitude 90 W,
2727#    includes most of Mexico, excluding what's mentioned below.
2728# 2- Zona Pacífico (Pacific Zone): Longitude 105 W, includes the
2729#    states of Baja California Sur; Chihuahua; Nayarit (excluding Bahía
2730#    de Banderas which lies in Central Zone); Sinaloa and Sonora.
2731# 3- Zona Noroeste (Northwest Zone): Longitude 120 W, includes the
2732#    state of Baja California.
2733# 4- Zona Sureste (Southeast Zone): Longitude 75 W, includes the state
2734#    of Quintana Roo.
2735# 5- The islands, reefs and keys shall take their timezone from the
2736#    longitude they are located at.
2737
2738# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
2739Rule	Mexico	1939	only	-	Feb	5	0:00	1:00	D
2740Rule	Mexico	1939	only	-	Jun	25	0:00	0	S
2741Rule	Mexico	1940	only	-	Dec	9	0:00	1:00	D
2742Rule	Mexico	1941	only	-	Apr	1	0:00	0	S
2743Rule	Mexico	1943	only	-	Dec	16	0:00	1:00	W # War
2744Rule	Mexico	1944	only	-	May	1	0:00	0	S
2745Rule	Mexico	1950	only	-	Feb	12	0:00	1:00	D
2746Rule	Mexico	1950	only	-	Jul	30	0:00	0	S
2747Rule	Mexico	1996	2000	-	Apr	Sun>=1	2:00	1:00	D
2748Rule	Mexico	1996	2000	-	Oct	lastSun	2:00	0	S
2749Rule	Mexico	2001	only	-	May	Sun>=1	2:00	1:00	D
2750Rule	Mexico	2001	only	-	Sep	lastSun	2:00	0	S
2751Rule	Mexico	2002	max	-	Apr	Sun>=1	2:00	1:00	D
2752Rule	Mexico	2002	max	-	Oct	lastSun	2:00	0	S
2753# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
2754# Quintana Roo; represented by Cancún
2755Zone America/Cancun	-5:47:04 -	LMT	1922 Jan  1  0:12:56
2756			-6:00	-	CST	1981 Dec 23
2757			-5:00	Mexico	E%sT	1998 Aug  2  2:00
2758			-6:00	Mexico	C%sT	2015 Feb  1  2:00
2759			-5:00	-	EST
2760# Campeche, Yucatán; represented by Mérida
2761Zone America/Merida	-5:58:28 -	LMT	1922 Jan  1  0:01:32
2762			-6:00	-	CST	1981 Dec 23
2763			-5:00	-	EST	1982 Dec  2
2764			-6:00	Mexico	C%sT
2765# Coahuila, Nuevo León, Tamaulipas (near US border)
2766# This includes the following municipalities:
2767#   in Coahuila: Ocampo, Acuña, Zaragoza, Jiménez, Piedras Negras, Nava,
2768#     Guerrero, Hidalgo.
2769#   in Nuevo León: Anáhuac, Los Aldama.
2770#   in Tamaulipas: Nuevo Laredo, Guerrero, Mier, Miguel Alemán, Camargo,
2771#     Gustavo Díaz Ordaz, Reynosa, Río Bravo, Valle Hermoso, Matamoros.
2772# See: Inicia mañana Horario de Verano en zona fronteriza, El Universal,
2773# 2016-03-12
2774# http://www.eluniversal.com.mx/articulo/estados/2016/03/12/inicia-manana-horario-de-verano-en-zona-fronteriza
2775Zone America/Matamoros	-6:40:00 -	LMT	1921 Dec 31 23:20:00
2776			-6:00	-	CST	1988
2777			-6:00	US	C%sT	1989
2778			-6:00	Mexico	C%sT	2010
2779			-6:00	US	C%sT
2780# Durango; Coahuila, Nuevo León, Tamaulipas (away from US border)
2781Zone America/Monterrey	-6:41:16 -	LMT	1921 Dec 31 23:18:44
2782			-6:00	-	CST	1988
2783			-6:00	US	C%sT	1989
2784			-6:00	Mexico	C%sT
2785# Central Mexico
2786Zone America/Mexico_City -6:36:36 -	LMT	1922 Jan  1  0:23:24
2787			-7:00	-	MST	1927 Jun 10 23:00
2788			-6:00	-	CST	1930 Nov 15
2789			-7:00	-	MST	1931 May  1 23:00
2790			-6:00	-	CST	1931 Oct
2791			-7:00	-	MST	1932 Apr  1
2792			-6:00	Mexico	C%sT	2001 Sep 30  2:00
2793			-6:00	-	CST	2002 Feb 20
2794			-6:00	Mexico	C%sT
2795# Chihuahua (near US border)
2796# This includes the municipalities of Janos, Ascensión, Juárez, Guadalupe,
2797# Práxedis G Guerrero, Coyame del Sotol, Ojinaga, and Manuel Benavides.
2798# (See the 2016-03-12 El Universal source mentioned above.)
2799Zone America/Ojinaga	-6:57:40 -	LMT	1922 Jan  1  0:02:20
2800			-7:00	-	MST	1927 Jun 10 23:00
2801			-6:00	-	CST	1930 Nov 15
2802			-7:00	-	MST	1931 May  1 23:00
2803			-6:00	-	CST	1931 Oct
2804			-7:00	-	MST	1932 Apr  1
2805			-6:00	-	CST	1996
2806			-6:00	Mexico	C%sT	1998
2807			-6:00	-	CST	1998 Apr Sun>=1  3:00
2808			-7:00	Mexico	M%sT	2010
2809			-7:00	US	M%sT
2810# Chihuahua (away from US border)
2811Zone America/Chihuahua	-7:04:20 -	LMT	1921 Dec 31 23:55:40
2812			-7:00	-	MST	1927 Jun 10 23:00
2813			-6:00	-	CST	1930 Nov 15
2814			-7:00	-	MST	1931 May  1 23:00
2815			-6:00	-	CST	1931 Oct
2816			-7:00	-	MST	1932 Apr  1
2817			-6:00	-	CST	1996
2818			-6:00	Mexico	C%sT	1998
2819			-6:00	-	CST	1998 Apr Sun>=1  3:00
2820			-7:00	Mexico	M%sT
2821# Sonora
2822Zone America/Hermosillo	-7:23:52 -	LMT	1921 Dec 31 23:36:08
2823			-7:00	-	MST	1927 Jun 10 23:00
2824			-6:00	-	CST	1930 Nov 15
2825			-7:00	-	MST	1931 May  1 23:00
2826			-6:00	-	CST	1931 Oct
2827			-7:00	-	MST	1932 Apr  1
2828			-6:00	-	CST	1942 Apr 24
2829			-7:00	-	MST	1949 Jan 14
2830			-8:00	-	PST	1970
2831			-7:00	Mexico	M%sT	1999
2832			-7:00	-	MST
2833
2834# From Alexander Krivenyshev (2010-04-21):
2835# According to news, Bahía de Banderas (Mexican state of Nayarit)
2836# changed time zone UTC-7 to new time zone UTC-6 on April 4, 2010 (to
2837# share the same time zone as nearby city Puerto Vallarta, Jalisco).
2838#
2839# (Spanish)
2840# Bahía de Banderas homologa su horario al del centro del
2841# país, a partir de este domingo
2842# http://www.nayarit.gob.mx/notes.asp?id=20748
2843#
2844# Bahía de Banderas homologa su horario con el del Centro del
2845# País
2846# http://www.bahiadebanderas.gob.mx/principal/index.php?option=com_content&view=article&id=261:bahia-de-banderas-homologa-su-horario-con-el-del-centro-del-pais&catid=42:comunicacion-social&Itemid=50
2847#
2848# (English)
2849# Puerto Vallarta and Bahía de Banderas: One Time Zone
2850# http://virtualvallarta.com/puertovallarta/puertovallarta/localnews/2009-12-03-Puerto-Vallarta-and-Bahia-de-Banderas-One-Time-Zone.shtml
2851# http://www.worldtimezone.com/dst_news/dst_news_mexico08.html
2852#
2853# "Mexico's Senate approved the amendments to the Mexican Schedule System that
2854# will allow Bahía de Banderas and Puerto Vallarta to share the same time
2855# zone ..."
2856# Baja California Sur, Nayarit, Sinaloa
2857
2858# From Arthur David Olson (2010-05-01):
2859# Use "Bahia_Banderas" to keep the name to fourteen characters.
2860
2861# Mazatlán
2862Zone America/Mazatlan	-7:05:40 -	LMT	1921 Dec 31 23:54:20
2863			-7:00	-	MST	1927 Jun 10 23:00
2864			-6:00	-	CST	1930 Nov 15
2865			-7:00	-	MST	1931 May  1 23:00
2866			-6:00	-	CST	1931 Oct
2867			-7:00	-	MST	1932 Apr  1
2868			-6:00	-	CST	1942 Apr 24
2869			-7:00	-	MST	1949 Jan 14
2870			-8:00	-	PST	1970
2871			-7:00	Mexico	M%sT
2872
2873# Bahía de Banderas
2874Zone America/Bahia_Banderas	-7:01:00 -	LMT	1921 Dec 31 23:59:00
2875			-7:00	-	MST	1927 Jun 10 23:00
2876			-6:00	-	CST	1930 Nov 15
2877			-7:00	-	MST	1931 May  1 23:00
2878			-6:00	-	CST	1931 Oct
2879			-7:00	-	MST	1932 Apr  1
2880			-6:00	-	CST	1942 Apr 24
2881			-7:00	-	MST	1949 Jan 14
2882			-8:00	-	PST	1970
2883			-7:00	Mexico	M%sT	2010 Apr  4  2:00
2884			-6:00	Mexico	C%sT
2885
2886# Baja California
2887Zone America/Tijuana	-7:48:04 -	LMT	1922 Jan  1  0:11:56
2888			-7:00	-	MST	1924
2889			-8:00	-	PST	1927 Jun 10 23:00
2890			-7:00	-	MST	1930 Nov 15
2891			-8:00	-	PST	1931 Apr  1
2892			-8:00	1:00	PDT	1931 Sep 30
2893			-8:00	-	PST	1942 Apr 24
2894			-8:00	1:00	PWT	1945 Aug 14 23:00u
2895			-8:00	1:00	PPT	1945 Nov 12 # Peace
2896			-8:00	-	PST	1948 Apr  5
2897			-8:00	1:00	PDT	1949 Jan 14
2898			-8:00	-	PST	1954
2899			-8:00	CA	P%sT	1961
2900			-8:00	-	PST	1976
2901			-8:00	US	P%sT	1996
2902			-8:00	Mexico	P%sT	2001
2903			-8:00	US	P%sT	2002 Feb 20
2904			-8:00	Mexico	P%sT	2010
2905			-8:00	US	P%sT
2906# From Paul Eggert (2006-03-22):
2907# Formerly there was an America/Ensenada zone, which differed from
2908# America/Tijuana only in that it did not observe DST from 1976
2909# through 1995.  This was as per Shanks (1999).  But Shanks & Pottenger say
2910# Ensenada did not observe DST from 1948 through 1975.  Guy Harris reports
2911# that the 1987 OAG says "Only Ensenada, Mexicali, San Felipe and
2912# Tijuana observe DST," which agrees with Shanks & Pottenger but implies that
2913# DST-observance was a town-by-town matter back then.  This concerns
2914# data after 1970 so most likely there should be at least one Zone
2915# other than America/Tijuana for Baja, but it's not clear yet what its
2916# name or contents should be.
2917#
2918# From Paul Eggert (2015-10-08):
2919# Formerly there was an America/Santa_Isabel zone, but this appears to
2920# have come from a misreading of
2921# http://dof.gob.mx/nota_detalle.php?codigo=5127480&fecha=06/01/2010
2922# It has been moved to the 'backward' file.
2923#
2924#
2925# Revillagigedo Is
2926# no information
2927
2928###############################################################################
2929
2930# Anguilla
2931# Antigua and Barbuda
2932# See America/Port_of_Spain.
2933
2934# Bahamas
2935#
2936# For 1899 Milne gives -5:09:29.5; round that.
2937#
2938# From Sue Williams (2006-12-07):
2939# The Bahamas announced about a month ago that they plan to change their DST
2940# rules to sync with the U.S. starting in 2007....
2941# http://www.jonesbahamas.com/?c=45&a=10412
2942
2943# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
2944Rule	Bahamas	1964	1975	-	Oct	lastSun	2:00	0	S
2945Rule	Bahamas	1964	1975	-	Apr	lastSun	2:00	1:00	D
2946# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
2947Zone	America/Nassau	-5:09:30 -	LMT	1912 Mar 2
2948			-5:00	Bahamas	E%sT	1976
2949			-5:00	US	E%sT
2950
2951# Barbados
2952
2953# For 1899 Milne gives -3:58:29.2; round that.
2954
2955# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
2956Rule	Barb	1977	only	-	Jun	12	2:00	1:00	D
2957Rule	Barb	1977	1978	-	Oct	Sun>=1	2:00	0	S
2958Rule	Barb	1978	1980	-	Apr	Sun>=15	2:00	1:00	D
2959Rule	Barb	1979	only	-	Sep	30	2:00	0	S
2960Rule	Barb	1980	only	-	Sep	25	2:00	0	S
2961# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
2962Zone America/Barbados	-3:58:29 -	LMT	1924 # Bridgetown
2963			-3:58:29 -	BMT	1932 # Bridgetown Mean Time
2964			-4:00	Barb	A%sT
2965
2966# Belize
2967# Whitman entirely disagrees with Shanks; go with Shanks & Pottenger.
2968# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
2969Rule	Belize	1918	1942	-	Oct	Sun>=2	0:00	0:30	-0530
2970Rule	Belize	1919	1943	-	Feb	Sun>=9	0:00	0	CST
2971Rule	Belize	1973	only	-	Dec	 5	0:00	1:00	CDT
2972Rule	Belize	1974	only	-	Feb	 9	0:00	0	CST
2973Rule	Belize	1982	only	-	Dec	18	0:00	1:00	CDT
2974Rule	Belize	1983	only	-	Feb	12	0:00	0	CST
2975# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
2976Zone	America/Belize	-5:52:48 -	LMT	1912 Apr
2977			-6:00	Belize	%s
2978
2979# Bermuda
2980
2981# For 1899 Milne gives -4:19:18.3 as the meridian of the clock tower,
2982# Bermuda dockyard, Ireland I; round that.
2983
2984# From Dan Jones, reporting in The Royal Gazette (2006-06-26):
2985
2986# Next year, however, clocks in the US will go forward on the second Sunday
2987# in March, until the first Sunday in November.  And, after the Time Zone
2988# (Seasonal Variation) Bill 2006 was passed in the House of Assembly on
2989# Friday, the same thing will happen in Bermuda.
2990# http://www.theroyalgazette.com/apps/pbcs.dll/article?AID=/20060529/NEWS/105290135
2991
2992# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
2993Zone Atlantic/Bermuda	-4:19:18 -	LMT	1930 Jan  1  2:00 # Hamilton
2994			-4:00	-	AST	1974 Apr 28  2:00
2995			-4:00	Canada	A%sT	1976
2996			-4:00	US	A%sT
2997
2998# Cayman Is
2999# See America/Panama.
3000
3001# Costa Rica
3002
3003# Milne gives -5:36:13.3 as San José mean time; round to nearest.
3004
3005# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
3006Rule	CR	1979	1980	-	Feb	lastSun	0:00	1:00	D
3007Rule	CR	1979	1980	-	Jun	Sun>=1	0:00	0	S
3008Rule	CR	1991	1992	-	Jan	Sat>=15	0:00	1:00	D
3009# IATA SSIM (1991-09) says the following was at 1:00;
3010# go with Shanks & Pottenger.
3011Rule	CR	1991	only	-	Jul	 1	0:00	0	S
3012Rule	CR	1992	only	-	Mar	15	0:00	0	S
3013# There are too many San Josés elsewhere, so we'll use 'Costa Rica'.
3014# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
3015Zone America/Costa_Rica	-5:36:13 -	LMT	1890        # San José
3016			-5:36:13 -	SJMT	1921 Jan 15 # San José Mean Time
3017			-6:00	CR	C%sT
3018# Coco
3019# no information; probably like America/Costa_Rica
3020
3021# Cuba
3022
3023# From Paul Eggert (2013-02-21):
3024# Milne gives -5:28:50.45 for the observatory at Havana, -5:29:23.57
3025# for the port, and -5:30 for meteorological observations.
3026# For now, stick with Shanks & Pottenger.
3027
3028# From Arthur David Olson (1999-03-29):
3029# The 1999-03-28 exhibition baseball game held in Havana, Cuba, between
3030# the Cuban National Team and the Baltimore Orioles was carried live on
3031# the Orioles Radio Network, including affiliate WTOP in Washington, DC.
3032# During the game, play-by-play announcer Jim Hunter noted that
3033# "We'll be losing two hours of sleep...Cuba switched to Daylight Saving
3034# Time today."  (The "two hour" remark referred to losing one hour of
3035# sleep on 1999-03-28 - when the announcers were in Cuba as it switched
3036# to DST - and one more hour on 1999-04-04 - when the announcers will have
3037# returned to Baltimore, which switches on that date.)
3038
3039# From Steffen Thorsen (2013-11-11):
3040# DST start in Cuba in 2004 ... does not follow the same rules as the
3041# years before.  The correct date should be Sunday 2004-03-28 00:00 ...
3042# https://web.archive.org/web/20040402060750/http://www.granma.cu/espanol/2004/marzo/sab27/reloj.html
3043
3044# From Evert van der Veer via Steffen Thorsen (2004-10-28):
3045# Cuba is not going back to standard time this year.
3046# From Paul Eggert (2006-03-22):
3047# http://www.granma.cu/ingles/2004/septiembre/juev30/41medid-i.html
3048# says that it's due to a problem at the Antonio Guiteras
3049# thermoelectric plant, and says "This October there will be no return
3050# to normal hours (after daylight saving time)".
3051# For now, let's assume that it's a temporary measure.
3052
3053# From Carlos A. Carnero Delgado (2005-11-12):
3054# This year (just like in 2004-2005) there's no change in time zone
3055# adjustment in Cuba.  We will stay in daylight saving time:
3056# http://www.granma.cu/espanol/2005/noviembre/mier9/horario.html
3057
3058# From Jesper Nørgaard Welen (2006-10-21):
3059# An article in GRANMA INTERNACIONAL claims that Cuba will end
3060# the 3 years of permanent DST next weekend, see
3061# http://www.granma.cu/ingles/2006/octubre/lun16/43horario.html
3062# "On Saturday night, October 28 going into Sunday, October 29, at 01:00,
3063# watches should be set back one hour - going back to 00:00 hours - returning
3064# to the normal schedule....
3065
3066# From Paul Eggert (2007-03-02):
3067# <http://www.granma.cubaweb.cu/english/news/art89.html>, dated yesterday,
3068# says Cuban clocks will advance at midnight on March 10.
3069# For lack of better information, assume Cuba will use US rules,
3070# except that it switches at midnight standard time as usual.
3071#
3072# From Steffen Thorsen (2007-10-25):
3073# Carlos Alberto Fonseca Arauz informed me that Cuba will end DST one week
3074# earlier - on the last Sunday of October, just like in 2006.
3075#
3076# He supplied these references:
3077#
3078# http://www.prensalatina.com.mx/article.asp?ID=%7B4CC32C1B-A9F7-42FB-8A07-8631AFC923AF%7D&language=ES
3079# http://actualidad.terra.es/sociedad/articulo/cuba_llama_ahorrar_energia_cambio_1957044.htm
3080#
3081# From Alex Krivenyshev (2007-10-25):
3082# Here is also article from Granma (Cuba):
3083#
3084# Regirá el Horario Normal desde el próximo domingo 28 de octubre
3085# http://www.granma.cubaweb.cu/2007/10/24/nacional/artic07.html
3086#
3087# http://www.worldtimezone.com/dst_news/dst_news_cuba03.html
3088
3089# From Arthur David Olson (2008-03-09):
3090# I'm in Maryland which is now observing United States Eastern Daylight
3091# Time. At 9:44 local time I used RealPlayer to listen to
3092# http://media.enet.cu/radioreloj
3093# a Cuban information station, and heard
3094# the time announced as "ocho cuarenta y cuatro" ("eight forty-four"),
3095# indicating that Cuba is still on standard time.
3096
3097# From Steffen Thorsen (2008-03-12):
3098# It seems that Cuba will start DST on Sunday, 2007-03-16...
3099# It was announced yesterday, according to this source (in Spanish):
3100# http://www.nnc.cubaweb.cu/marzo-2008/cien-1-11-3-08.htm
3101#
3102# Some more background information is posted here:
3103# https://www.timeanddate.com/news/time/cuba-starts-dst-march-16.html
3104#
3105# The article also says that Cuba has been observing DST since 1963,
3106# while Shanks (and tzdata) has 1965 as the first date (except in the
3107# 1940's). Many other web pages in Cuba also claim that it has been
3108# observed since 1963, but with the exception of 1970 - an exception
3109# which is not present in tzdata/Shanks. So there is a chance we need to
3110# change some historic records as well.
3111#
3112# One example:
3113# http://www.radiohc.cu/espanol/noticias/mar07/11mar/hor.htm
3114
3115# From Jesper Nørgaard Welen (2008-03-13):
3116# The Cuban time change has just been confirmed on the most authoritative
3117# web site, the Granma.  Please check out
3118# http://www.granma.cubaweb.cu/2008/03/13/nacional/artic10.html
3119#
3120# Basically as expected after Steffen Thorsen's information, the change
3121# will take place midnight between Saturday and Sunday.
3122
3123# From Arthur David Olson (2008-03-12):
3124# Assume Sun>=15 (third Sunday) going forward.
3125
3126# From Alexander Krivenyshev (2009-03-04)
3127# According to the Radio Reloj - Cuba will start Daylight Saving Time on
3128# midnight between Saturday, March 07, 2009 and Sunday, March 08, 2009-
3129# not on midnight March 14 / March 15 as previously thought.
3130#
3131# http://www.worldtimezone.com/dst_news/dst_news_cuba05.html
3132# (in Spanish)
3133
3134# From Arthur David Olson (2009-03-09)
3135# I listened over the Internet to
3136# http://media.enet.cu/readioreloj
3137# this morning; when it was 10:05 a. m. here in Bethesda, Maryland the
3138# the time was announced as "diez cinco" - the same time as here, indicating
3139# that has indeed switched to DST. Assume second Sunday from 2009 forward.
3140
3141# From Steffen Thorsen (2011-03-08):
3142# Granma announced that Cuba is going to start DST on 2011-03-20 00:00:00
3143# this year. Nothing about the end date known so far (if that has
3144# changed at all).
3145#
3146# Source:
3147# http://granma.co.cu/2011/03/08/nacional/artic01.html
3148#
3149# Our info:
3150# https://www.timeanddate.com/news/time/cuba-starts-dst-2011.html
3151#
3152# From Steffen Thorsen (2011-10-30)
3153# Cuba will end DST two weeks later this year. Instead of going back
3154# tonight, it has been delayed to 2011-11-13 at 01:00.
3155#
3156# One source (Spanish)
3157# http://www.radioangulo.cu/noticias/cuba/17105-cuba-restablecera-el-horario-del-meridiano-de-greenwich.html
3158#
3159# Our page:
3160# https://www.timeanddate.com/news/time/cuba-time-changes-2011.html
3161#
3162# From Steffen Thorsen (2012-03-01)
3163# According to Radio Reloj, Cuba will start DST on Midnight between March
3164# 31 and April 1.
3165#
3166# Radio Reloj has the following info (Spanish):
3167# http://www.radioreloj.cu/index.php/noticias-radio-reloj/71-miscelaneas/7529-cuba-aplicara-el-horario-de-verano-desde-el-1-de-abril
3168#
3169# Our info on it:
3170# https://www.timeanddate.com/news/time/cuba-starts-dst-2012.html
3171
3172# From Steffen Thorsen (2012-11-03):
3173# Radio Reloj and many other sources report that Cuba is changing back
3174# to standard time on 2012-11-04:
3175# http://www.radioreloj.cu/index.php/noticias-radio-reloj/36-nacionales/9961-regira-horario-normal-en-cuba-desde-el-domingo-cuatro-de-noviembre
3176# From Paul Eggert (2012-11-03):
3177# For now, assume the future rule is first Sunday in November.
3178
3179# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
3180Rule	Cuba	1928	only	-	Jun	10	0:00	1:00	D
3181Rule	Cuba	1928	only	-	Oct	10	0:00	0	S
3182Rule	Cuba	1940	1942	-	Jun	Sun>=1	0:00	1:00	D
3183Rule	Cuba	1940	1942	-	Sep	Sun>=1	0:00	0	S
3184Rule	Cuba	1945	1946	-	Jun	Sun>=1	0:00	1:00	D
3185Rule	Cuba	1945	1946	-	Sep	Sun>=1	0:00	0	S
3186Rule	Cuba	1965	only	-	Jun	1	0:00	1:00	D
3187Rule	Cuba	1965	only	-	Sep	30	0:00	0	S
3188Rule	Cuba	1966	only	-	May	29	0:00	1:00	D
3189Rule	Cuba	1966	only	-	Oct	2	0:00	0	S
3190Rule	Cuba	1967	only	-	Apr	8	0:00	1:00	D
3191Rule	Cuba	1967	1968	-	Sep	Sun>=8	0:00	0	S
3192Rule	Cuba	1968	only	-	Apr	14	0:00	1:00	D
3193Rule	Cuba	1969	1977	-	Apr	lastSun	0:00	1:00	D
3194Rule	Cuba	1969	1971	-	Oct	lastSun	0:00	0	S
3195Rule	Cuba	1972	1974	-	Oct	8	0:00	0	S
3196Rule	Cuba	1975	1977	-	Oct	lastSun	0:00	0	S
3197Rule	Cuba	1978	only	-	May	7	0:00	1:00	D
3198Rule	Cuba	1978	1990	-	Oct	Sun>=8	0:00	0	S
3199Rule	Cuba	1979	1980	-	Mar	Sun>=15	0:00	1:00	D
3200Rule	Cuba	1981	1985	-	May	Sun>=5	0:00	1:00	D
3201Rule	Cuba	1986	1989	-	Mar	Sun>=14	0:00	1:00	D
3202Rule	Cuba	1990	1997	-	Apr	Sun>=1	0:00	1:00	D
3203Rule	Cuba	1991	1995	-	Oct	Sun>=8	0:00s	0	S
3204Rule	Cuba	1996	only	-	Oct	 6	0:00s	0	S
3205Rule	Cuba	1997	only	-	Oct	12	0:00s	0	S
3206Rule	Cuba	1998	1999	-	Mar	lastSun	0:00s	1:00	D
3207Rule	Cuba	1998	2003	-	Oct	lastSun	0:00s	0	S
3208Rule	Cuba	2000	2003	-	Apr	Sun>=1	0:00s	1:00	D
3209Rule	Cuba	2004	only	-	Mar	lastSun	0:00s	1:00	D
3210Rule	Cuba	2006	2010	-	Oct	lastSun	0:00s	0	S
3211Rule	Cuba	2007	only	-	Mar	Sun>=8	0:00s	1:00	D
3212Rule	Cuba	2008	only	-	Mar	Sun>=15	0:00s	1:00	D
3213Rule	Cuba	2009	2010	-	Mar	Sun>=8	0:00s	1:00	D
3214Rule	Cuba	2011	only	-	Mar	Sun>=15	0:00s	1:00	D
3215Rule	Cuba	2011	only	-	Nov	13	0:00s	0	S
3216Rule	Cuba	2012	only	-	Apr	1	0:00s	1:00	D
3217Rule	Cuba	2012	max	-	Nov	Sun>=1	0:00s	0	S
3218Rule	Cuba	2013	max	-	Mar	Sun>=8	0:00s	1:00	D
3219
3220# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
3221Zone	America/Havana	-5:29:28 -	LMT	1890
3222			-5:29:36 -	HMT	1925 Jul 19 12:00 # Havana MT
3223			-5:00	Cuba	C%sT
3224
3225# Dominica
3226# See America/Port_of_Spain.
3227
3228# Dominican Republic
3229
3230# From Steffen Thorsen (2000-10-30):
3231# Enrique Morales reported to me that the Dominican Republic has changed the
3232# time zone to Eastern Standard Time as of Sunday 29 at 2 am....
3233# http://www.listin.com.do/antes/261000/republica/princi.html
3234
3235# From Paul Eggert (2000-12-04):
3236# That URL (2000-10-26, in Spanish) says they planned to use US-style DST.
3237
3238# From Rives McDow (2000-12-01):
3239# Dominican Republic changed its mind and presidential decree on Tuesday,
3240# November 28, 2000, with a new decree.  On Sunday, December 3 at 1:00 AM the
3241# Dominican Republic will be reverting to 8 hours from the International Date
3242# Line, and will not be using DST in the foreseeable future.  The reason they
3243# decided to use DST was to be in synch with Puerto Rico, who was also going
3244# to implement DST.  When Puerto Rico didn't implement DST, the president
3245# decided to revert.
3246
3247
3248# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
3249Rule	DR	1966	only	-	Oct	30	0:00	1:00	EDT
3250Rule	DR	1967	only	-	Feb	28	0:00	0	EST
3251Rule	DR	1969	1973	-	Oct	lastSun	0:00	0:30	-0430
3252Rule	DR	1970	only	-	Feb	21	0:00	0	EST
3253Rule	DR	1971	only	-	Jan	20	0:00	0	EST
3254Rule	DR	1972	1974	-	Jan	21	0:00	0	EST
3255# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
3256Zone America/Santo_Domingo -4:39:36 -	LMT	1890
3257			-4:40	-	SDMT	1933 Apr  1 12:00 # S. Dom. MT
3258			-5:00	DR	%s	1974 Oct 27
3259			-4:00	-	AST	2000 Oct 29  2:00
3260			-5:00	US	E%sT	2000 Dec  3  1:00
3261			-4:00	-	AST
3262
3263# El Salvador
3264
3265# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
3266Rule	Salv	1987	1988	-	May	Sun>=1	0:00	1:00	D
3267Rule	Salv	1987	1988	-	Sep	lastSun	0:00	0	S
3268# There are too many San Salvadors elsewhere, so use America/El_Salvador
3269# instead of America/San_Salvador.
3270# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
3271Zone America/El_Salvador -5:56:48 -	LMT	1921 # San Salvador
3272			-6:00	Salv	C%sT
3273
3274# Grenada
3275# Guadeloupe
3276# St Barthélemy
3277# St Martin (French part)
3278# See America/Port_of_Spain.
3279
3280# Guatemala
3281#
3282# From Gwillim Law (2006-04-22), after a heads-up from Oscar van Vlijmen:
3283# Diario Co Latino, at
3284# <http://www.diariocolatino.com/internacionales/detalles.asp?NewsID=8079>,
3285# says in an article dated 2006-04-19 that the Guatemalan government had
3286# decided on that date to advance official time by 60 minutes, to lessen the
3287# impact of the elevated cost of oil....  Daylight saving time will last from
3288# 2006-04-29 24:00 (Guatemalan standard time) to 2006-09-30 (time unspecified).
3289# From Paul Eggert (2006-06-22):
3290# The Ministry of Energy and Mines, press release CP-15/2006
3291# (2006-04-19), says DST ends at 24:00.  See
3292# http://www.sieca.org.gt/Sitio_publico/Energeticos/Doc/Medidas/Cambio_Horario_Nac_190406.pdf
3293
3294# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
3295Rule	Guat	1973	only	-	Nov	25	0:00	1:00	D
3296Rule	Guat	1974	only	-	Feb	24	0:00	0	S
3297Rule	Guat	1983	only	-	May	21	0:00	1:00	D
3298Rule	Guat	1983	only	-	Sep	22	0:00	0	S
3299Rule	Guat	1991	only	-	Mar	23	0:00	1:00	D
3300Rule	Guat	1991	only	-	Sep	 7	0:00	0	S
3301Rule	Guat	2006	only	-	Apr	30	0:00	1:00	D
3302Rule	Guat	2006	only	-	Oct	 1	0:00	0	S
3303# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
3304Zone America/Guatemala	-6:02:04 -	LMT	1918 Oct 5
3305			-6:00	Guat	C%sT
3306
3307# Haiti
3308# From Gwillim Law (2005-04-15):
3309# Risto O. Nykänen wrote me that Haiti is now on DST.
3310# I searched for confirmation, and I found a press release
3311# on the Web page of the Haitian Consulate in Chicago (2005-03-31),
3312# <http://www.haitianconsulate.org/time.doc>.  Translated from French, it says:
3313#
3314#  "The Prime Minister's Communication Office notifies the public in general
3315#   and the press in particular that, following a decision of the Interior
3316#   Ministry and the Territorial Collectivities [I suppose that means the
3317#   provinces], Haiti will move to Eastern Daylight Time in the night from next
3318#   Saturday the 2nd to Sunday the 3rd.
3319#
3320#  "Consequently, the Prime Minister's Communication Office wishes to inform
3321#   the population that the country's clocks will be set forward one hour
3322#   starting at midnight.  This provision will hold until the last Saturday in
3323#   October 2005.
3324#
3325#  "Port-au-Prince, March 31, 2005"
3326#
3327# From Steffen Thorsen (2006-04-04):
3328# I have been informed by users that Haiti observes DST this year like
3329# last year, so the current "only" rule for 2005 might be changed to a
3330# "max" rule or to last until 2006. (Who knows if they will observe DST
3331# next year or if they will extend their DST like US/Canada next year).
3332#
3333# I have found this article about it (in French):
3334# http://www.haitipressnetwork.com/news.cfm?articleID=7612
3335#
3336# The reason seems to be an energy crisis.
3337
3338# From Stephen Colebourne (2007-02-22):
3339# Some IATA info: Haiti won't be having DST in 2007.
3340
3341# From Steffen Thorsen (2012-03-11):
3342# According to several news sources, Haiti will observe DST this year,
3343# apparently using the same start and end date as USA/Canada.
3344# So this means they have already changed their time.
3345#
3346# http://www.alterpresse.org/spip.php?article12510
3347# http://radiovision2000haiti.net/home/?p=13253
3348#
3349# From Arthur David Olson (2012-03-11):
3350# The alterpresse.org source seems to show a US-style leap from 2:00 a.m. to
3351# 3:00 a.m. rather than the traditional Haitian jump at midnight.
3352# Assume a US-style fall back as well.
3353
3354# From Steffen Thorsen (2013-03-10):
3355# It appears that Haiti is observing DST this year as well, same rules
3356# as US/Canada.  They did it last year as well, and it looks like they
3357# are going to observe DST every year now...
3358#
3359# http://radiovision2000haiti.net/public/haiti-avis-changement-dheure-dimanche/
3360# http://www.canalplushaiti.net/?p=6714
3361
3362# From Steffen Thorsen (2016-03-12):
3363# Jean Antoine, editor of www.haiti-reference.com informed us that Haiti
3364# are not going on DST this year.  Several other resources confirm this: ...
3365# https://www.radiotelevisioncaraibes.com/presse/heure_d_t_pas_de_changement_d_heure_pr_vu_pour_cet_ann_e.html
3366# https://www.vantbefinfo.com/changement-dheure-pas-pour-haiti/
3367# http://news.anmwe.com/haiti-lheure-nationale-ne-sera-ni-avancee-ni-reculee-cette-annee/
3368
3369# From Steffen Thorsen (2017-03-12):
3370# We have received 4 mails from different people telling that Haiti
3371# has started DST again today, and this source seems to confirm that,
3372# I have not been able to find a more authoritative source:
3373# https://www.haitilibre.com/en/news-20319-haiti-notices-time-change-in-haiti.html
3374
3375# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
3376Rule	Haiti	1983	only	-	May	8	0:00	1:00	D
3377Rule	Haiti	1984	1987	-	Apr	lastSun	0:00	1:00	D
3378Rule	Haiti	1983	1987	-	Oct	lastSun	0:00	0	S
3379# Shanks & Pottenger say AT is 2:00, but IATA SSIM (1991/1997) says 1:00s.
3380# Go with IATA.
3381Rule	Haiti	1988	1997	-	Apr	Sun>=1	1:00s	1:00	D
3382Rule	Haiti	1988	1997	-	Oct	lastSun	1:00s	0	S
3383Rule	Haiti	2005	2006	-	Apr	Sun>=1	0:00	1:00	D
3384Rule	Haiti	2005	2006	-	Oct	lastSun	0:00	0	S
3385Rule	Haiti	2012	2015	-	Mar	Sun>=8	2:00	1:00	D
3386Rule	Haiti	2012	2015	-	Nov	Sun>=1	2:00	0	S
3387Rule	Haiti	2017	max	-	Mar	Sun>=8	2:00	1:00	D
3388Rule	Haiti	2017	max	-	Nov	Sun>=1	2:00	0	S
3389# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
3390Zone America/Port-au-Prince -4:49:20 -	LMT	1890
3391			-4:49	-	PPMT	1917 Jan 24 12:00 # P-a-P MT
3392			-5:00	Haiti	E%sT
3393
3394# Honduras
3395# Shanks & Pottenger say 1921 Jan 1; go with Whitman's more precise Apr 1.
3396
3397# From Paul Eggert (2006-05-05):
3398# worldtimezone.com reports a 2006-05-02 Spanish-language AP article
3399# saying Honduras will start using DST midnight Saturday, effective 4
3400# months until September.  La Tribuna reported today
3401# <http://www.latribuna.hn/99299.html> that Manuel Zelaya, the president
3402# of Honduras, refused to back down on this.
3403
3404# From Jesper Nørgaard Welen (2006-08-08):
3405# It seems that Honduras has returned from DST to standard time this Monday at
3406# 00:00 hours (prolonging Sunday to 25 hours duration).
3407# http://www.worldtimezone.com/dst_news/dst_news_honduras04.html
3408
3409# From Paul Eggert (2006-08-08):
3410# Also see Diario El Heraldo, The country returns to standard time (2006-08-08).
3411# http://www.elheraldo.hn/nota.php?nid=54941&sec=12
3412# It mentions executive decree 18-2006.
3413
3414# From Steffen Thorsen (2006-08-17):
3415# Honduras will observe DST from 2007 to 2009, exact dates are not
3416# published, I have located this authoritative source:
3417# http://www.presidencia.gob.hn/noticia.aspx?nId=47
3418
3419# From Steffen Thorsen (2007-03-30):
3420# http://www.laprensahn.com/pais_nota.php?id04962=7386
3421# So it seems that Honduras will not enter DST this year....
3422
3423# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
3424Rule	Hond	1987	1988	-	May	Sun>=1	0:00	1:00	D
3425Rule	Hond	1987	1988	-	Sep	lastSun	0:00	0	S
3426Rule	Hond	2006	only	-	May	Sun>=1	0:00	1:00	D
3427Rule	Hond	2006	only	-	Aug	Mon>=1	0:00	0	S
3428# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
3429Zone America/Tegucigalpa -5:48:52 -	LMT	1921 Apr
3430			-6:00	Hond	C%sT
3431#
3432# Great Swan I ceded by US to Honduras in 1972
3433
3434# Jamaica
3435# Shanks & Pottenger give -5:07:12, but Milne records -5:07:10.41 from an
3436# unspecified official document, and says "This time is used throughout the
3437# island".  Go with Milne.  Round to the nearest second as required by zic.
3438#
3439# Shanks & Pottenger give April 28 for the 1974 spring-forward transition, but
3440# Lance Neita writes that Prime Minister Michael Manley decreed it January 5.
3441# Assume Neita meant Jan 6 02:00, the same as the US.  Neita also writes that
3442# Manley's supporters associated this act with Manley's nickname "Joshua"
3443# (recall that in the Bible the sun stood still at Joshua's request),
3444# and with the Rod of Correction which Manley said he had received from
3445# Haile Selassie, Emperor of Ethiopia.  See:
3446# Neita L. The politician in all of us. Jamaica Observer 2014-09-20
3447# http://www.jamaicaobserver.com/columns/The-politician-in-all-of-us_17573647
3448#
3449# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
3450Zone	America/Jamaica	-5:07:10 -	LMT	1890        # Kingston
3451			-5:07:10 -	KMT	1912 Feb    # Kingston Mean Time
3452			-5:00	-	EST	1974
3453			-5:00	US	E%sT	1984
3454			-5:00	-	EST
3455
3456# Martinique
3457# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
3458Zone America/Martinique	-4:04:20 -      LMT	1890        # Fort-de-France
3459			-4:04:20 -	FFMT	1911 May    # Fort-de-France MT
3460			-4:00	-	AST	1980 Apr  6
3461			-4:00	1:00	ADT	1980 Sep 28
3462			-4:00	-	AST
3463
3464# Montserrat
3465# See America/Port_of_Spain.
3466
3467# Nicaragua
3468#
3469# This uses Shanks & Pottenger for times before 2005.
3470#
3471# From Steffen Thorsen (2005-04-12):
3472# I've got reports from 8 different people that Nicaragua just started
3473# DST on Sunday 2005-04-10, in order to save energy because of
3474# expensive petroleum.  The exact end date for DST is not yet
3475# announced, only "September" but some sites also say "mid-September".
3476# Some background information is available on the President's official site:
3477# http://www.presidencia.gob.ni/Presidencia/Files_index/Secretaria/Notas%20de%20Prensa/Presidente/2005/ABRIL/Gobierno-de-nicaragua-adelanta-hora-oficial-06abril.htm
3478# The Decree, no 23-2005 is available here:
3479# http://www.presidencia.gob.ni/buscador_gaceta/BD/DECRETOS/2005/Decreto%2023-2005%20Se%20adelanta%20en%20una%20hora%20en%20todo%20el%20territorio%20nacional%20apartir%20de%20las%2024horas%20del%2009%20de%20Abril.pdf
3480#
3481# From Paul Eggert (2005-05-01):
3482# The decree doesn't say anything about daylight saving, but for now let's
3483# assume that it is daylight saving....
3484#
3485# From Gwillim Law (2005-04-21):
3486# The Associated Press story on the time change, which can be found at
3487# http://www.lapalmainteractivo.com/guias/content/gen/ap/America_Latina/AMC_GEN_NICARAGUA_HORA.html
3488# and elsewhere, says (fifth paragraph, translated from Spanish): "The last
3489# time that a change of clocks was applied to save energy was in the year 2000
3490# during the Arnoldo Alemán administration."...
3491# The northamerica file says that Nicaragua has been on UTC-6 continuously
3492# since December 1998.  I wasn't able to find any details of Nicaraguan time
3493# changes in 2000.  Perhaps a note could be added to the northamerica file, to
3494# the effect that we have indirect evidence that DST was observed in 2000.
3495#
3496# From Jesper Nørgaard Welen (2005-11-02):
3497# Nicaragua left DST the 2005-10-02 at 00:00 (local time).
3498# http://www.presidencia.gob.ni/presidencia/files_index/secretaria/comunicados/2005/septiembre/26septiembre-cambio-hora.htm
3499# (2005-09-26)
3500#
3501# From Jesper Nørgaard Welen (2006-05-05):
3502# http://www.elnuevodiario.com.ni/2006/05/01/nacionales/18410
3503# (my informal translation)
3504# By order of the president of the republic, Enrique Bolaños, Nicaragua
3505# advanced by sixty minutes their official time, yesterday at 2 in the
3506# morning, and will stay that way until 30th of September.
3507#
3508# From Jesper Nørgaard Welen (2006-09-30):
3509# http://www.presidencia.gob.ni/buscador_gaceta/BD/DECRETOS/2006/D-063-2006P-PRN-Cambio-Hora.pdf
3510# My informal translation runs:
3511# The natural sun time is restored in all the national territory, in that the
3512# time is returned one hour at 01:00 am of October 1 of 2006.
3513#
3514# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
3515Rule	Nic	1979	1980	-	Mar	Sun>=16	0:00	1:00	D
3516Rule	Nic	1979	1980	-	Jun	Mon>=23	0:00	0	S
3517Rule	Nic	2005	only	-	Apr	10	0:00	1:00	D
3518Rule	Nic	2005	only	-	Oct	Sun>=1	0:00	0	S
3519Rule	Nic	2006	only	-	Apr	30	2:00	1:00	D
3520Rule	Nic	2006	only	-	Oct	Sun>=1	1:00	0	S
3521# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
3522Zone	America/Managua	-5:45:08 -	LMT	1890
3523			-5:45:12 -	MMT	1934 Jun 23 # Managua Mean Time?
3524			-6:00	-	CST	1973 May
3525			-5:00	-	EST	1975 Feb 16
3526			-6:00	Nic	C%sT	1992 Jan  1  4:00
3527			-5:00	-	EST	1992 Sep 24
3528			-6:00	-	CST	1993
3529			-5:00	-	EST	1997
3530			-6:00	Nic	C%sT
3531
3532# Panama
3533# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
3534Zone	America/Panama	-5:18:08 -	LMT	1890
3535			-5:19:36 -	CMT	1908 Apr 22 # Colón Mean Time
3536			-5:00	-	EST
3537Link America/Panama America/Cayman
3538
3539# Puerto Rico
3540# There are too many San Juans elsewhere, so we'll use 'Puerto_Rico'.
3541# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
3542Zone America/Puerto_Rico -4:24:25 -	LMT	1899 Mar 28 12:00 # San Juan
3543			-4:00	-	AST	1942 May  3
3544			-4:00	US	A%sT	1946
3545			-4:00	-	AST
3546
3547# St Kitts-Nevis
3548# St Lucia
3549# See America/Port_of_Spain.
3550
3551# St Pierre and Miquelon
3552# There are too many St Pierres elsewhere, so we'll use 'Miquelon'.
3553# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
3554Zone America/Miquelon	-3:44:40 -	LMT	1911 May 15 # St Pierre
3555			-4:00	-	AST	1980 May
3556			-3:00	-	-03	1987
3557			-3:00	Canada	-03/-02
3558
3559# St Vincent and the Grenadines
3560# See America/Port_of_Spain.
3561
3562# Turks and Caicos
3563#
3564# From Chris Dunn in
3565# https://bugs.debian.org/415007
3566# (2007-03-15): In the Turks & Caicos Islands (America/Grand_Turk) the
3567# daylight saving dates for time changes have been adjusted to match
3568# the recent U.S. change of dates.
3569#
3570# From Brian Inglis (2007-04-28):
3571# http://www.turksandcaicos.tc/calendar/index.htm [2007-04-26]
3572# there is an entry for Nov 4 "Daylight Savings Time Ends 2007" and three
3573# rows before that there is an out of date entry for Oct:
3574# "Eastern Standard Times Begins 2007
3575# Clocks are set back one hour at 2:00 a.m. local Daylight Saving Time"
3576# indicating that the normal ET rules are followed.
3577#
3578# From Paul Eggert (2014-08-19):
3579# The 2014-08-13 Cabinet meeting decided to stay on UT -04 year-round.  See:
3580# http://tcweeklynews.com/daylight-savings-time-to-be-maintained-p5353-127.htm
3581# Model this as a switch from EST/EDT to AST ...
3582# From Chris Walton (2014-11-04):
3583# ... the TCI government appears to have delayed the switch to
3584# "permanent daylight saving time" by one year....
3585# http://tcweeklynews.com/time-change-to-go-ahead-this-november-p5437-127.htm
3586#
3587# From the Turks & Caicos Cabinet (2017-07-20), heads-up from Steffen Thorsen:
3588# ... agreed to the reintroduction in TCI of Daylight Saving Time (DST)
3589# during the summer months and Standard Time, also known as Local
3590# Time, during the winter months with effect from April 2018 ...
3591# https://www.gov.uk/government/news/turks-and-caicos-post-cabinet-meeting-statement--3
3592#
3593# From Paul Eggert (2017-08-26):
3594# The date of effect of the spring 2018 change appears to be March 11,
3595# which makes more sense.  See: Hamilton D. Time change back
3596# by March 2018 for TCI. Magnetic Media. 2017-08-25.
3597# http://magneticmediatv.com/2017/08/time-change-back-by-march-2018-for-tci/
3598#
3599# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
3600Zone America/Grand_Turk	-4:44:32 -	LMT	1890
3601			-5:07:10 -	KMT	1912 Feb # Kingston Mean Time
3602			-5:00	-	EST	1979
3603			-5:00	US	E%sT	2015 Nov Sun>=1 2:00
3604			-4:00	-	AST	2018 Mar 11 3:00
3605			-5:00	US	E%sT
3606
3607# British Virgin Is
3608# Virgin Is
3609# See America/Port_of_Spain.
3610
3611
3612# Local Variables:
3613# coding: utf-8
3614# End:
3615