1 # tzdb data for North and Central America and environs
3 # This file is in the public domain, so clarified as of
4 # 2009-05-17 by Arthur David Olson.
6 # also includes Central America and the Caribbean
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.
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).
17 ###############################################################################
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.
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:
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.
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
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).
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.
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:
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.
83 # -- Robertson Davies, The diary of Samuel Marchbanks,
84 # Clarke, Irwin (1947), XIX, Sunday
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
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".
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
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.
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.
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.
137 # From Paul Eggert (2017-09-23):
138 # This was the V-J Day issue of the Clamdigger, a Rowayton, CT newsletter.
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.
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:
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
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."
165 # He had scored a 20-second scoop on other broadcasters.
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.
173 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
174 Rule US 1918 1919 - Mar lastSun 2:00 1:00 D
175 Rule US 1918 1919 - Oct lastSun 2:00 0 S
176 Rule US 1942 only - Feb 9 2:00 1:00 W # War
177 Rule US 1945 only - Aug 14 23:00u 1:00 P # Peace
178 Rule US 1945 only - Sep 30 2:00 0 S
179 Rule US 1967 2006 - Oct lastSun 2:00 0 S
180 Rule US 1967 1973 - Apr lastSun 2:00 1:00 D
181 Rule US 1974 only - Jan 6 2:00 1:00 D
182 Rule US 1975 only - Feb lastSun 2:00 1:00 D
183 Rule US 1976 1986 - Apr lastSun 2:00 1:00 D
184 Rule US 1987 2006 - Apr Sun>=1 2:00 1:00 D
185 Rule US 2007 max - Mar Sun>=8 2:00 1:00 D
186 Rule US 2007 max - Nov Sun>=1 2:00 0 S
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.
199 # Zone NAME STDOFF RULES FORMAT [UNTIL]
202 Zone HST -10:00 - HST
203 Zone EST5EDT -5:00 US E%sT
204 Zone CST6CDT -6:00 US C%sT
205 Zone MST7MDT -7:00 US M%sT
206 Zone PST8PDT -8:00 US P%sT
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
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
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:
236 # United States standard eastern time
237 # United States standard mountain time
238 # United States standard central time
239 # United States standard Pacific time
241 # United States standard Alaska time
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.
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)
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".
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
289 # From Arthur David Olson, 2005-08-09
290 # The following was signed into law on 2005-08-08.
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
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.
309 # US eastern time, represented by New York
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
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.
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
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
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
350 # Rule NAME FROM TO - IN ON AT SAVE LETTER
351 Rule NYC 1920 only - Mar lastSun 2:00 1:00 D
352 Rule NYC 1920 only - Oct lastSun 2:00 0 S
353 Rule NYC 1921 1966 - Apr lastSun 2:00 1:00 D
354 Rule NYC 1921 1954 - Sep lastSun 2:00 0 S
355 Rule NYC 1955 1966 - Oct lastSun 2:00 0 S
356 # Zone NAME STDOFF RULES FORMAT [UNTIL]
357 Zone America/New_York -4:56:02 - LMT 1883 Nov 18 12:03:58
364 # US central time, represented by Chicago
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
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
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/
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....
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
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!)
406 # From Paul Eggert (2015-12-25):
407 # Assume this practice predates 1970, so Fort Pierre can use America/Chicago.
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:
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:
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.'
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."
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/
434 # Rule NAME FROM TO - IN ON AT SAVE LETTER
435 Rule Chicago 1920 only - Jun 13 2:00 1:00 D
436 Rule Chicago 1920 1921 - Oct lastSun 2:00 0 S
437 Rule Chicago 1921 only - Mar lastSun 2:00 1:00 D
438 Rule Chicago 1922 1966 - Apr lastSun 2:00 1:00 D
439 Rule Chicago 1922 1954 - Sep lastSun 2:00 0 S
440 Rule Chicago 1955 1966 - Oct lastSun 2:00 0 S
441 # Zone NAME STDOFF RULES FORMAT [UNTIL]
442 Zone America/Chicago -5:50:36 - LMT 1883 Nov 18 12:09:24
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
448 -6:00 Chicago C%sT 1967
450 # Oliver County, ND switched from mountain to central time on 1992-10-25.
451 Zone 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
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>.
461 Zone 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
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
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".
478 Zone 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
482 # US mountain time, represented by Denver
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
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/
503 # Rule NAME FROM TO - IN ON AT SAVE LETTER
504 Rule Denver 1920 1921 - Mar lastSun 2:00 1:00 D
505 Rule Denver 1920 only - Oct lastSun 2:00 0 S
506 Rule Denver 1921 only - May 22 2:00 0 S
507 Rule Denver 1965 1966 - Apr lastSun 2:00 1:00 D
508 Rule Denver 1965 1966 - Oct lastSun 2:00 0 S
509 # Zone NAME STDOFF RULES FORMAT [UNTIL]
510 Zone America/Denver -6:59:56 - LMT 1883 Nov 18 12:00:04
512 -7:00 Denver M%sT 1942
514 -7:00 Denver M%sT 1967
517 # US Pacific time, represented by Los Angeles
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
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
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
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.
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).
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
556 # Rule NAME FROM TO - IN ON AT SAVE LETTER
557 Rule CA 1948 only - Mar 14 2:01 1:00 D
558 Rule CA 1949 only - Jan 1 2:00 0 S
559 Rule CA 1950 1966 - Apr lastSun 1:00 1:00 D
560 Rule CA 1950 1961 - Sep lastSun 2:00 0 S
561 Rule CA 1962 1966 - Oct lastSun 2:00 0 S
562 # Zone NAME STDOFF RULES FORMAT [UNTIL]
563 Zone America/Los_Angeles -7:52:58 - LMT 1883 Nov 18 12:07:02
569 # AK%sT is the modern abbreviation for -09 per USNO.
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.
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.
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
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/
609 # From Arthur David Olson (2011-02-01):
610 # Here's database-relevant material from the 2001 "Alaska History" article:
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
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.
621 # On October 28 [1983]...the Metlakatla Indian Community Council voted
622 # unanimously to keep the reservation on Pacific Time.
624 # According to DOT official Joanne Petrie, Indian reservations are not
625 # bound to follow time zones imposed by neighboring jurisdictions.
627 # (The last is consistent with how the database now handles the Navajo
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.
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.
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/
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/
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/
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.
670 # Zone NAME STDOFF RULES FORMAT [UNTIL]
671 Zone America/Juneau 15:02:19 - LMT 1867 Oct 19 15:33:32
672 -8:57:41 - LMT 1900 Aug 20 12:00
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
681 Zone America/Sitka 14:58:47 - LMT 1867 Oct 19 15:30
682 -9:01:13 - LMT 1900 Aug 20 12:00
686 -8:00 US P%sT 1983 Oct 30 2:00
687 -9:00 US Y%sT 1983 Nov 30
689 Zone America/Metlakatla 15:13:42 - LMT 1867 Oct 19 15:44:55
690 -8:46:18 - LMT 1900 Aug 20 12:00
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
699 Zone America/Yakutat 14:41:05 - LMT 1867 Oct 19 15:12:18
700 -9:18:55 - LMT 1900 Aug 20 12:00
704 -9:00 US Y%sT 1983 Nov 30
706 Zone America/Anchorage 14:00:24 - LMT 1867 Oct 19 14:31:37
707 -9:59:36 - LMT 1900 Aug 20 12:00
709 -10:00 US A%sT 1967 Apr
711 -10:00 US AH%sT 1983 Oct 30 2:00
712 -9:00 US Y%sT 1983 Nov 30
714 Zone America/Nome 12:58:22 - LMT 1867 Oct 19 13:29:35
715 -11:01:38 - LMT 1900 Aug 20 12:00
718 -11:00 - NST 1967 Apr
720 -11:00 US B%sT 1983 Oct 30 2:00
721 -9:00 US Y%sT 1983 Nov 30
723 Zone America/Adak 12:13:22 - LMT 1867 Oct 19 12:44:35
724 -11:46:38 - LMT 1900 Aug 20 12:00
727 -11:00 - NST 1967 Apr
729 -11:00 US B%sT 1983 Oct 30 2:00
730 -10:00 US AH%sT 1983 Nov 30
732 # The following switches don't quite make our 1970 cutoff.
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.
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:
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."
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)."
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."
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.
790 # Zone NAME STDOFF RULES FORMAT [UNTIL]
791 Zone 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
797 # Now we turn to US areas that have diverged from the consensus since 1970.
799 # Arizona mostly uses MST.
801 # From Paul Eggert (2002-10-20):
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.
817 # Shanks says the 1944 experiment came to an end on 1944-03-17.
818 # Go with the Arizona State Library instead.
820 # Zone NAME STDOFF RULES FORMAT [UNTIL]
821 Zone 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
826 -7:00 US M%sT 1968 Mar 21
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.)
835 # From Paul Eggert (2013-08-26):
836 # See America/Denver for a zone appropriate for the Navajo Nation.
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.
846 # Zone NAME STDOFF RULES FORMAT [UNTIL]
847 Zone America/Boise -7:44:49 - LMT 1883 Nov 18 12:15:11
848 -8:00 US P%sT 1923 May 13 2:00
850 -7:00 - MST 1974 Feb 3 2:00
855 # For a map of Indiana's time zone regions, see:
856 # https://en.wikipedia.org/wiki/Time_in_Indiana
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/
874 # From Paul Eggert (2007-08-17):
875 # Since 1970, most of Indiana has been like America/Indiana/Indianapolis,
876 # with the following exceptions:
878 # - Gibson, Jasper, Lake, LaPorte, Newton, Porter, Posey, Spencer,
879 # Vanderburgh, and Warrick counties have been like America/Chicago.
881 # - Dearborn and Ohio counties have been like America/New_York.
883 # - Clark, Floyd, and Harrison counties have been like
884 # America/Kentucky/Louisville.
886 # - Crawford, Daviess, Dubois, Knox, Martin, Perry, Pike, Pulaski, Starke,
887 # and Switzerland counties have their own time zone histories as noted below.
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.
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'.
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.
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
914 # Rule NAME FROM TO - IN ON AT SAVE LETTER
915 Rule Indianapolis 1941 only - Jun 22 2:00 1:00 D
916 Rule Indianapolis 1941 1954 - Sep lastSun 2:00 0 S
917 Rule Indianapolis 1946 1954 - Apr lastSun 2:00 1:00 D
918 # Zone NAME STDOFF RULES FORMAT [UNTIL]
919 Zone America/Indiana/Indianapolis -5:44:38 - LMT 1883 Nov 18 12:15:22
921 -6:00 Indianapolis C%sT 1942
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
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
934 Rule Marengo 1951 only - Apr lastSun 2:00 1:00 D
935 Rule Marengo 1951 only - Sep lastSun 2:00 0 S
936 Rule Marengo 1954 1960 - Apr lastSun 2:00 1:00 D
937 Rule Marengo 1954 1960 - Sep lastSun 2:00 0 S
938 # Zone NAME STDOFF RULES FORMAT [UNTIL]
939 Zone America/Indiana/Marengo -5:45:23 - LMT 1883 Nov 18 12:14:37
941 -6:00 Marengo C%sT 1961 Apr 30 2:00
943 -5:00 US E%sT 1974 Jan 6 2:00
944 -6:00 1:00 CDT 1974 Oct 27 2:00
949 # Daviess, Dubois, Knox, and Martin Counties, Indiana,
950 # switched from eastern to central time in April 2006, then switched back
952 # Rule NAME FROM TO - IN ON AT SAVE LETTER
953 Rule Vincennes 1946 only - Apr lastSun 2:00 1:00 D
954 Rule Vincennes 1946 only - Sep lastSun 2:00 0 S
955 Rule Vincennes 1953 1954 - Apr lastSun 2:00 1:00 D
956 Rule Vincennes 1953 1959 - Sep lastSun 2:00 0 S
957 Rule Vincennes 1955 only - May 1 0:00 1:00 D
958 Rule Vincennes 1956 1963 - Apr lastSun 2:00 1:00 D
959 Rule Vincennes 1960 only - Oct lastSun 2:00 0 S
960 Rule Vincennes 1961 only - Sep lastSun 2:00 0 S
961 Rule Vincennes 1962 1963 - Oct lastSun 2:00 0 S
962 # Zone NAME STDOFF RULES FORMAT [UNTIL]
963 Zone America/Indiana/Vincennes -5:50:07 - LMT 1883 Nov 18 12:09:53
965 -6:00 Vincennes C%sT 1964 Apr 26 2:00
968 -5:00 - EST 2006 Apr 2 2:00
969 -6:00 US C%sT 2007 Nov 4 2:00
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
978 Rule Perry 1955 only - May 1 0:00 1:00 D
979 Rule Perry 1955 1960 - Sep lastSun 2:00 0 S
980 Rule Perry 1956 1963 - Apr lastSun 2:00 1:00 D
981 Rule Perry 1961 1963 - Oct lastSun 2:00 0 S
982 # Zone NAME STDOFF RULES FORMAT [UNTIL]
983 Zone America/Indiana/Tell_City -5:47:03 - LMT 1883 Nov 18 12:12:57
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
989 -5:00 - EST 2006 Apr 2 2:00
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
995 Rule Pike 1955 only - May 1 0:00 1:00 D
996 Rule Pike 1955 1960 - Sep lastSun 2:00 0 S
997 Rule Pike 1956 1964 - Apr lastSun 2:00 1:00 D
998 Rule Pike 1961 1964 - Oct lastSun 2:00 0 S
999 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1000 Zone America/Indiana/Petersburg -5:49:07 - LMT 1883 Nov 18 12:10:53
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
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
1015 # Rule NAME FROM TO - IN ON AT SAVE LETTER
1016 Rule Starke 1947 1961 - Apr lastSun 2:00 1:00 D
1017 Rule Starke 1947 1954 - Sep lastSun 2:00 0 S
1018 Rule Starke 1955 1956 - Oct lastSun 2:00 0 S
1019 Rule Starke 1957 1958 - Sep lastSun 2:00 0 S
1020 Rule Starke 1959 1961 - Oct lastSun 2:00 0 S
1021 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1022 Zone America/Indiana/Knox -5:46:30 - LMT 1883 Nov 18 12:13:30
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
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
1033 Rule Pulaski 1946 1960 - Apr lastSun 2:00 1:00 D
1034 Rule Pulaski 1946 1954 - Sep lastSun 2:00 0 S
1035 Rule Pulaski 1955 1956 - Oct lastSun 2:00 0 S
1036 Rule Pulaski 1957 1960 - Sep lastSun 2:00 0 S
1037 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1038 Zone America/Indiana/Winamac -5:46:25 - LMT 1883 Nov 18 12:13:35
1040 -6:00 Pulaski C%sT 1961 Apr 30 2:00
1043 -5:00 - EST 2006 Apr 2 2:00
1044 -6:00 US C%sT 2007 Mar 11 2:00
1047 # Switzerland County, Indiana, did not observe DST from 1973 through 2005.
1048 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1049 Zone America/Indiana/Vevay -5:40:16 - LMT 1883 Nov 18 12:19:44
1050 -6:00 US C%sT 1954 Apr 25 2:00
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.
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.
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
1075 Rule Louisville 1921 only - May 1 2:00 1:00 D
1076 Rule Louisville 1921 only - Sep 1 2:00 0 S
1077 Rule Louisville 1941 only - Apr lastSun 2:00 1:00 D
1078 Rule Louisville 1941 only - Sep lastSun 2:00 0 S
1079 Rule Louisville 1946 only - Apr lastSun 0:01 1:00 D
1080 Rule Louisville 1946 only - Jun 2 2:00 0 S
1081 Rule Louisville 1950 1961 - Apr lastSun 2:00 1:00 D
1082 Rule Louisville 1950 1955 - Sep lastSun 2:00 0 S
1083 Rule Louisville 1956 1961 - Oct lastSun 2:00 0 S
1084 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1085 Zone America/Kentucky/Louisville -5:43:02 - LMT 1883 Nov 18 12:16:58
1087 -6:00 Louisville C%sT 1942
1089 -6:00 Louisville C%sT 1961 Jul 23 2:00
1091 -5:00 US E%sT 1974 Jan 6 2:00
1092 -6:00 1:00 CDT 1974 Oct 27 2:00
1095 # Wayne County, Kentucky
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.
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).
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
1119 Zone America/Kentucky/Monticello -5:39:24 - LMT 1883 Nov 18 12:20:36
1122 -6:00 US C%sT 2000 Oct 29 2:00
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
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.
1150 # From Bob Devine (1988-01-28):
1151 # Michigan didn't observe DST from 1968 to 1973.
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)
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
1166 # This story is too entertaining to be false, so go with Howse over Shanks.
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.
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.
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
1189 Rule Detroit 1948 only - Apr lastSun 2:00 1:00 D
1190 Rule Detroit 1948 only - Sep lastSun 2:00 0 S
1191 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1192 Zone America/Detroit -5:32:11 - LMT 1905
1193 -6:00 - CST 1915 May 15 2:00
1196 -5:00 Detroit E%sT 1967 Jun 14 0:01
1200 -5:00 - EST 1975 Apr 27 2:00
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
1206 Rule Menominee 1946 only - Apr lastSun 2:00 1:00 D
1207 Rule Menominee 1946 only - Sep lastSun 2:00 0 S
1208 Rule Menominee 1966 only - Apr lastSun 2:00 1:00 D
1209 Rule Menominee 1966 only - Oct lastSun 2:00 0 S
1210 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1211 Zone America/Menominee -5:50:27 - LMT 1885 Sep 18 12:00
1213 -6:00 Menominee C%sT 1969 Apr 27 2:00
1214 -5:00 - EST 1973 Apr 29 2:00
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).
1228 ################################################################################
1231 # From Paul Eggert (2017-02-10):
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.
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.
1245 # Other sources occasionally used include:
1247 # Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94
1248 # <https://www.jstor.org/stable/1774359>.
1250 # Pearce C. The Great Daylight Saving Time Controversy.
1251 # Australian Ebook Publisher. 2017. ISBN 978-1-925516-96-8.
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.
1257 # William Willett, The Waste of Daylight, 19th edition
1258 # <http://cs.ucla.edu/~eggert/The-Waste-of-Daylight-19th.pdf>
1261 # See the 'europe' file for Greenland.
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....
1269 # UTC Standard time Daylight saving time
1270 # offset French English French English
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
1281 # HN: Heure Normale ST: Standard Time
1282 # HA: Heure Avancée DT: Daylight saving Time
1284 # A: de l'Atlantique Atlantic
1285 # C: du Centre Central
1286 # E: de l'Est Eastern
1289 # P: du Pacifique Pacific
1294 # From Paul Eggert (1994-11-22):
1295 # Alas, this sort of thing must be handled by localization software.
1297 # Unless otherwise specified, the data entries for Canada are all from Shanks
1300 # From Chris Walton (2006-04-01, 2006-04-25, 2006-06-26, 2007-01-31,
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
1308 # Daylight saving time will be extended by four weeks starting in 2007....
1309 # https://www.novascotia.ca/just/regulations/rg2/2006/ma1206.pdf
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
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
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
1324 # P.E.I. will follow US rules....
1325 # http://www.assembly.pe.ca/bills/pdf_chapter/62/3/chapter-41.pdf
1327 # Province of Newfoundland and Labrador....
1328 # http://www.hoa.gov.nl.ca/hoa/bills/Bill0634.htm
1331 # https://www.gov.yk.ca/legislation/regs/oic2006_127.pdf
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
1338 # http://www.exec.gov.nt.ca/currentnews/currentPR.asp?mode=archive
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
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.
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.
1356 # From Paul Eggert (2006-06-27):
1357 # For now, assume all of DST-observing Canada will fall into line with the
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.
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.
1375 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
1376 Rule Canada 1918 only - Apr 14 2:00 1:00 D
1377 Rule Canada 1918 only - Oct 27 2:00 0 S
1378 Rule Canada 1942 only - Feb 9 2:00 1:00 W # War
1379 Rule Canada 1945 only - Aug 14 23:00u 1:00 P # Peace
1380 Rule Canada 1945 only - Sep 30 2:00 0 S
1381 Rule Canada 1974 1986 - Apr lastSun 2:00 1:00 D
1382 Rule Canada 1974 2006 - Oct lastSun 2:00 0 S
1383 Rule Canada 1987 2006 - Apr Sun>=1 2:00 1:00 D
1384 Rule Canada 2007 max - Mar Sun>=8 2:00 1:00 D
1385 Rule Canada 2007 max - Nov Sun>=1 2:00 0 S
1388 # Newfoundland and Labrador
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.
1398 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
1399 Rule StJohns 1917 only - Apr 8 2:00 1:00 D
1400 Rule StJohns 1917 only - Sep 17 2:00 0 S
1401 # Whitman gives 1919 Apr 5 and 1920 Apr 5; go with Shanks & Pottenger.
1402 Rule StJohns 1919 only - May 5 23:00 1:00 D
1403 Rule StJohns 1919 only - Aug 12 23:00 0 S
1404 # For 1931-1935 Whitman gives Apr same date; go with Shanks & Pottenger.
1405 Rule StJohns 1920 1935 - May Sun>=1 23:00 1:00 D
1406 Rule 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 &
1409 Rule StJohns 1936 1941 - May Mon>=9 0:00 1:00 D
1410 Rule 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.
1416 Rule StJohns 1946 1950 - May Sun>=8 2:00 1:00 D
1417 Rule StJohns 1946 1950 - Oct Sun>=2 2:00 0 S
1418 Rule StJohns 1951 1986 - Apr lastSun 2:00 1:00 D
1419 Rule StJohns 1951 1959 - Sep lastSun 2:00 0 S
1420 Rule 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.
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.
1432 # http://www.assembly.nl.ca/legislation/sr/annualstatutes/2011/1106.chp.htm
1434 # MICHAEL PELLEY | Manager of Enterprise Architecture - Solution Delivery
1435 # Office of the Chief Information Officer
1437 # Government of Newfoundland & Labrador
1439 Rule StJohns 1987 only - Apr Sun>=1 0:01 1:00 D
1440 Rule StJohns 1987 2006 - Oct lastSun 0:01 0 S
1441 Rule StJohns 1988 only - Apr Sun>=1 0:01 2:00 DD
1442 Rule StJohns 1989 2006 - Apr Sun>=1 0:01 1:00 D
1443 Rule StJohns 2007 2011 - Mar Sun>=8 0:01 1:00 D
1444 Rule StJohns 2007 2010 - Nov Sun>=1 0:01 0 S
1446 # St John's has an apostrophe, but Posix file names can't have apostrophes.
1447 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1448 Zone 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
1457 # most of east Labrador
1459 # The name 'Happy Valley-Goose Bay' is too long; use 'Goose Bay'.
1460 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1461 Zone America/Goose_Bay -4:01:40 - LMT 1884 # Happy Valley-Goose Bay
1463 -3:30:52 Canada N%sT 1919
1464 -3:30:52 - NST 1935 Mar 30
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
1473 # west Labrador, Nova Scotia, Prince Edward I,
1474 # Îles-de-la-Madeleine, Listuguj reserve
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.
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
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.
1500 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
1501 Rule Halifax 1916 only - Apr 1 0:00 1:00 D
1502 Rule Halifax 1916 only - Oct 1 0:00 0 S
1503 Rule Halifax 1920 only - May 9 0:00 1:00 D
1504 Rule Halifax 1920 only - Aug 29 0:00 0 S
1505 Rule Halifax 1921 only - May 6 0:00 1:00 D
1506 Rule Halifax 1921 1922 - Sep 5 0:00 0 S
1507 Rule Halifax 1922 only - Apr 30 0:00 1:00 D
1508 Rule Halifax 1923 1925 - May Sun>=1 0:00 1:00 D
1509 Rule Halifax 1923 only - Sep 4 0:00 0 S
1510 Rule Halifax 1924 only - Sep 15 0:00 0 S
1511 Rule Halifax 1925 only - Sep 28 0:00 0 S
1512 Rule Halifax 1926 only - May 16 0:00 1:00 D
1513 Rule Halifax 1926 only - Sep 13 0:00 0 S
1514 Rule Halifax 1927 only - May 1 0:00 1:00 D
1515 Rule Halifax 1927 only - Sep 26 0:00 0 S
1516 Rule Halifax 1928 1931 - May Sun>=8 0:00 1:00 D
1517 Rule Halifax 1928 only - Sep 9 0:00 0 S
1518 Rule Halifax 1929 only - Sep 3 0:00 0 S
1519 Rule Halifax 1930 only - Sep 15 0:00 0 S
1520 Rule Halifax 1931 1932 - Sep Mon>=24 0:00 0 S
1521 Rule Halifax 1932 only - May 1 0:00 1:00 D
1522 Rule Halifax 1933 only - Apr 30 0:00 1:00 D
1523 Rule Halifax 1933 only - Oct 2 0:00 0 S
1524 Rule Halifax 1934 only - May 20 0:00 1:00 D
1525 Rule Halifax 1934 only - Sep 16 0:00 0 S
1526 Rule Halifax 1935 only - Jun 2 0:00 1:00 D
1527 Rule Halifax 1935 only - Sep 30 0:00 0 S
1528 Rule Halifax 1936 only - Jun 1 0:00 1:00 D
1529 Rule Halifax 1936 only - Sep 14 0:00 0 S
1530 Rule Halifax 1937 1938 - May Sun>=1 0:00 1:00 D
1531 Rule Halifax 1937 1941 - Sep Mon>=24 0:00 0 S
1532 Rule Halifax 1939 only - May 28 0:00 1:00 D
1533 Rule Halifax 1940 1941 - May Sun>=1 0:00 1:00 D
1534 Rule Halifax 1946 1949 - Apr lastSun 2:00 1:00 D
1535 Rule Halifax 1946 1949 - Sep lastSun 2:00 0 S
1536 Rule Halifax 1951 1954 - Apr lastSun 2:00 1:00 D
1537 Rule Halifax 1951 1954 - Sep lastSun 2:00 0 S
1538 Rule Halifax 1956 1959 - Apr lastSun 2:00 1:00 D
1539 Rule Halifax 1956 1959 - Sep lastSun 2:00 0 S
1540 Rule Halifax 1962 1973 - Apr lastSun 2:00 1:00 D
1541 Rule Halifax 1962 1973 - Oct lastSun 2:00 0 S
1542 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1543 Zone 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
1550 Zone America/Glace_Bay -3:59:48 - LMT 1902 Jun 15
1551 -4:00 Canada A%sT 1953
1552 -4:00 Halifax A%sT 1954
1554 -4:00 Halifax A%sT 1974
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.
1566 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
1567 Rule Moncton 1933 1935 - Jun Sun>=8 1:00 1:00 D
1568 Rule Moncton 1933 1935 - Sep Sun>=8 1:00 0 S
1569 Rule Moncton 1936 1938 - Jun Sun>=1 1:00 1:00 D
1570 Rule Moncton 1936 1938 - Sep Sun>=1 1:00 0 S
1571 Rule Moncton 1939 only - May 27 1:00 1:00 D
1572 Rule Moncton 1939 1941 - Sep Sat>=21 1:00 0 S
1573 Rule Moncton 1940 only - May 19 1:00 1:00 D
1574 Rule Moncton 1941 only - May 4 1:00 1:00 D
1575 Rule Moncton 1946 1972 - Apr lastSun 2:00 1:00 D
1576 Rule Moncton 1946 1956 - Sep lastSun 2:00 0 S
1577 Rule Moncton 1957 1972 - Oct lastSun 2:00 0 S
1578 Rule Moncton 1993 2006 - Apr Sun>=1 0:01 1:00 D
1579 Rule Moncton 1993 2006 - Oct lastSun 0:01 0 S
1580 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1581 Zone 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
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.
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.
1610 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1611 Zone America/Blanc-Sablon -3:48:28 - LMT 1884
1612 -4:00 Canada A%sT 1970
1617 # From Paul Eggert (2006-07-09):
1618 # Shanks & Pottenger write that since 1970 most of Ontario has been like
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.
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
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
1645 # Kenora, Ontario, was to abandon DST on 1914-06-01 (-05-21).
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
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.
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.
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:
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.
1676 # For the most part, the system works, Mayor Dennis Brown said.
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."
1682 # Walton also writes "Supposedly Pickle Lake and Mishkeegogamang
1683 # [New Osnaburgh] follow the same practice."
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.
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.
1700 # From Mark Brader (2010-03-06):
1702 # Currently the database has:
1706 # # From Paul Eggert (2006-07-09):
1707 # # Shanks & Pottenger write that since 1970 most of Ontario has been like
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.
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:
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.
1720 # Windsor is, of course, a lot larger than Nipigon.
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.
1725 # By the way, the article continues by noting that:
1727 # Some cities in the United States have pushed the deadline back
1728 # three weeks and will change over from daylight saving in October.
1730 # From Arthur David Olson (2010-07-17):
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,
1736 # http://adsabs.harvard.edu/full/1932JRASC..26...49S
1738 # It includes the text below (starting on page 57):
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:
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:
1755 # St. Lambert Cap de la Madelèine
1756 # Verdun Loretteville
1757 # Westmount Richmond
1758 # Outremont St. Jérôme
1759 # Longueuil Greenfield Park
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.
1770 # British Columbia Not used.
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.
1775 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
1776 Rule Toronto 1919 only - Mar 30 23:30 1:00 D
1777 Rule Toronto 1919 only - Oct 26 0:00 0 S
1778 Rule Toronto 1920 only - May 2 2:00 1:00 D
1779 Rule Toronto 1920 only - Sep 26 0:00 0 S
1780 Rule Toronto 1921 only - May 15 2:00 1:00 D
1781 Rule Toronto 1921 only - Sep 15 2:00 0 S
1782 Rule 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"
1785 Rule Toronto 1922 1926 - Sep Sun>=15 2:00 0 S
1786 Rule Toronto 1924 1927 - May Sun>=1 2:00 1:00 D
1787 Rule Toronto 1927 1937 - Sep Sun>=25 2:00 0 S
1788 Rule Toronto 1928 1937 - Apr Sun>=25 2:00 1:00 D
1789 Rule Toronto 1938 1940 - Apr lastSun 2:00 1:00 D
1790 Rule Toronto 1938 1939 - Sep lastSun 2:00 0 S
1791 Rule Toronto 1945 1946 - Sep lastSun 2:00 0 S
1792 Rule Toronto 1946 only - Apr lastSun 2:00 1:00 D
1793 Rule Toronto 1947 1949 - Apr lastSun 0:00 1:00 D
1794 Rule Toronto 1947 1948 - Sep lastSun 0:00 0 S
1795 Rule Toronto 1949 only - Nov lastSun 0:00 0 S
1796 Rule Toronto 1950 1973 - Apr lastSun 2:00 1:00 D
1797 Rule Toronto 1950 only - Nov lastSun 2:00 0 S
1798 Rule 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.
1803 Rule Toronto 1957 1973 - Oct lastSun 2:00 0 S
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."
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.
1823 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1824 Zone 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
1830 Zone America/Thunder_Bay -5:57:00 - LMT 1895
1833 -5:00 Canada E%sT 1970
1834 -5:00 Toronto E%sT 1973
1837 Zone 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
1841 Zone 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
1845 Zone 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
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).
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.
1873 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
1874 Rule Winn 1916 only - Apr 23 0:00 1:00 D
1875 Rule Winn 1916 only - Sep 17 0:00 0 S
1876 Rule Winn 1918 only - Apr 14 2:00 1:00 D
1877 Rule Winn 1918 only - Oct 27 2:00 0 S
1878 Rule Winn 1937 only - May 16 2:00 1:00 D
1879 Rule Winn 1937 only - Sep 26 2:00 0 S
1880 Rule Winn 1942 only - Feb 9 2:00 1:00 W # War
1881 Rule Winn 1945 only - Aug 14 23:00u 1:00 P # Peace
1882 Rule Winn 1945 only - Sep lastSun 2:00 0 S
1883 Rule Winn 1946 only - May 12 2:00 1:00 D
1884 Rule Winn 1946 only - Oct 13 2:00 0 S
1885 Rule Winn 1947 1949 - Apr lastSun 2:00 1:00 D
1886 Rule Winn 1947 1949 - Sep lastSun 2:00 0 S
1887 Rule Winn 1950 only - May 1 2:00 1:00 D
1888 Rule Winn 1950 only - Sep 30 2:00 0 S
1889 Rule Winn 1951 1960 - Apr lastSun 2:00 1:00 D
1890 Rule Winn 1951 1958 - Sep lastSun 2:00 0 S
1891 Rule Winn 1959 only - Oct lastSun 2:00 0 S
1892 Rule Winn 1960 only - Sep lastSun 2:00 0 S
1893 Rule Winn 1963 only - Apr lastSun 2:00 1:00 D
1894 Rule Winn 1963 only - Sep 22 2:00 0 S
1895 Rule Winn 1966 1986 - Apr lastSun 2:00s 1:00 D
1896 Rule Winn 1966 2005 - Oct lastSun 2:00s 0 S
1897 Rule Winn 1987 2005 - Apr Sun>=1 2:00s 1:00 D
1898 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1899 Zone America/Winnipeg -6:28:36 - LMT 1887 Jul 16
1900 -6:00 Winn C%sT 2006
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
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."
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.
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.
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.
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.
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.
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.
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
1964 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
1965 Rule Regina 1918 only - Apr 14 2:00 1:00 D
1966 Rule Regina 1918 only - Oct 27 2:00 0 S
1967 Rule Regina 1930 1934 - May Sun>=1 0:00 1:00 D
1968 Rule Regina 1930 1934 - Oct Sun>=1 0:00 0 S
1969 Rule Regina 1937 1941 - Apr Sun>=8 0:00 1:00 D
1970 Rule Regina 1937 only - Oct Sun>=8 0:00 0 S
1971 Rule Regina 1938 only - Oct Sun>=1 0:00 0 S
1972 Rule Regina 1939 1941 - Oct Sun>=8 0:00 0 S
1973 Rule Regina 1942 only - Feb 9 2:00 1:00 W # War
1974 Rule Regina 1945 only - Aug 14 23:00u 1:00 P # Peace
1975 Rule Regina 1945 only - Sep lastSun 2:00 0 S
1976 Rule Regina 1946 only - Apr Sun>=8 2:00 1:00 D
1977 Rule Regina 1946 only - Oct Sun>=8 2:00 0 S
1978 Rule Regina 1947 1957 - Apr lastSun 2:00 1:00 D
1979 Rule Regina 1947 1957 - Sep lastSun 2:00 0 S
1980 Rule Regina 1959 only - Apr lastSun 2:00 1:00 D
1981 Rule Regina 1959 only - Oct lastSun 2:00 0 S
1983 Rule Swift 1957 only - Apr lastSun 2:00 1:00 D
1984 Rule Swift 1957 only - Oct lastSun 2:00 0 S
1985 Rule Swift 1959 1961 - Apr lastSun 2:00 1:00 D
1986 Rule Swift 1959 only - Oct lastSun 2:00 0 S
1987 Rule Swift 1960 1961 - Sep lastSun 2:00 0 S
1988 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1989 Zone America/Regina -6:58:36 - LMT 1905 Sep
1990 -7:00 Regina M%sT 1960 Apr lastSun 2:00
1992 Zone 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
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
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.
2014 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
2015 Rule Edm 1918 1919 - Apr Sun>=8 2:00 1:00 D
2016 Rule Edm 1918 only - Oct 27 2:00 0 S
2017 Rule Edm 1919 only - May 27 2:00 0 S
2018 Rule Edm 1920 1923 - Apr lastSun 2:00 1:00 D
2019 Rule Edm 1920 only - Oct lastSun 2:00 0 S
2020 Rule Edm 1921 1923 - Sep lastSun 2:00 0 S
2021 Rule Edm 1942 only - Feb 9 2:00 1:00 W # War
2022 Rule Edm 1945 only - Aug 14 23:00u 1:00 P # Peace
2023 Rule Edm 1945 only - Sep lastSun 2:00 0 S
2024 Rule Edm 1947 only - Apr lastSun 2:00 1:00 D
2025 Rule Edm 1947 only - Sep lastSun 2:00 0 S
2026 Rule Edm 1972 1986 - Apr lastSun 2:00 1:00 D
2027 Rule Edm 1972 2006 - Oct lastSun 2:00 0 S
2028 # Zone NAME STDOFF RULES FORMAT [UNTIL]
2029 Zone America/Edmonton -7:33:52 - LMT 1906 Sep
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.
2042 # It seems though that (re: Creston) is not entirely correct:
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)
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.
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
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.
2075 # On Oct 27/1918 when daylight saving ended in the rest of Canada,
2076 # Creston did not change its clocks.
2078 # During WWII when the Federal Government legislated a mandatory clock change,
2079 # Creston did not oblige.
2081 # There is no guarantee that Creston will remain on Mountain Standard Time
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
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.
2093 # The transition dates (and times) are guesses.
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
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
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.
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.
2123 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
2124 Rule Vanc 1918 only - Apr 14 2:00 1:00 D
2125 Rule Vanc 1918 only - Oct 27 2:00 0 S
2126 Rule Vanc 1942 only - Feb 9 2:00 1:00 W # War
2127 Rule Vanc 1945 only - Aug 14 23:00u 1:00 P # Peace
2128 Rule Vanc 1945 only - Sep 30 2:00 0 S
2129 Rule Vanc 1946 1986 - Apr lastSun 2:00 1:00 D
2130 Rule Vanc 1946 only - Sep 29 2:00 0 S
2131 Rule Vanc 1947 1961 - Sep lastSun 2:00 0 S
2132 Rule Vanc 1962 2006 - Oct lastSun 2:00 0 S
2133 # Zone NAME STDOFF RULES FORMAT [UNTIL]
2134 Zone America/Vancouver -8:12:28 - LMT 1884
2135 -8:00 Vanc P%sT 1987
2137 Zone 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
2141 Zone America/Fort_Nelson -8:10:47 - LMT 1884
2142 -8:00 Vanc P%sT 1946
2144 -8:00 Vanc P%sT 1987
2145 -8:00 Canada P%sT 2015 Mar 8 2:00
2147 Zone America/Creston -7:46:04 - LMT 1884
2148 -7:00 - MST 1916 Oct 1
2149 -8:00 - PST 1918 Jun 2
2152 # Northwest Territories, Nunavut, Yukon
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.
2165 # From Brian Inglis (2015-04-14):
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.
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.
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.
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.
2197 # (1) Subject to this section, standard time shall be reckoned as nine
2198 # hours behind Greenwich Time and called Yukon Standard Time.
2200 # (2) Notwithstanding subsection (1), the Commissioner may make regulations
2201 # varying the manner of reckoning standard time.
2203 # * Yukon Territory Commissioner's Order 1966-20 Interpretation Ordinance
2204 # [no online source found]
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 ...
2211 # 1. Commissioner's Order 1966-20 dated at Whitehorse in the Yukon
2212 # Territory on 27th January, 1966, is hereby revoked.
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.
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.
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 ...
2228 # 1. Effective October 28, 1973 Commissioner's Order 1967/59 is hereby
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.
2236 # * O.I.C. 1980/02 INTERPRETATION ACT
2237 # [no online source found]
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 ...
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.
2249 # Dated ... 9th day of March, A.D., 1987.
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 ...
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.
2261 # 2. Order-in-Council 1987/56 is revoked.
2263 # 3. This order comes into force January 1, 2007.
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
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
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.
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.
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:
2288 # The following businesses and organizations in Pangnirtung use Central Time:
2290 # First Air, Power Corp, Nunavut Construction, Health Center, RCMP,
2291 # Eastern Arctic National Parks, A & D Specialist
2293 # The following businesses and organizations in Pangnirtung use Eastern Time:
2295 # Hamlet office, All other businesses, Both schools, Airport operator
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.
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.
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.
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.
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.
2339 # From Rives McDow (2001-01-20), quoting the Nunavut government:
2340 # The preceding decision came into effect at midnight, Saturday Nov 4, 2000.
2342 # From Paul Eggert (2000-12-04):
2343 # Let's just keep track of the official times for now.
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
2353 # [Also see <http://www.nunatsiaq.com/nunavut/nvt10309_06.html> (2001-03-09).]
2355 # From Gwillim Law (2005-05-21):
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.
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.
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
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.
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...
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...
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...
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.
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
2418 # http://www.uphere.ca/node/493
2420 # I sent Aziz an e-mail asking when Resolute Bay had stopped using
2421 # Eastern Standard Time.
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"
2428 # This of course conflicted with everything I had ascertained in November 2008.
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"
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.
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
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
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
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.
2464 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
2465 Rule NT_YK 1918 only - Apr 14 2:00 1:00 D
2466 Rule NT_YK 1918 only - Oct 27 2:00 0 S
2467 Rule NT_YK 1919 only - May 25 2:00 1:00 D
2468 Rule NT_YK 1919 only - Nov 1 0:00 0 S
2469 Rule NT_YK 1942 only - Feb 9 2:00 1:00 W # War
2470 Rule NT_YK 1945 only - Aug 14 23:00u 1:00 P # Peace
2471 Rule NT_YK 1945 only - Sep 30 2:00 0 S
2472 Rule NT_YK 1965 only - Apr lastSun 0:00 2:00 DD
2473 Rule NT_YK 1965 only - Oct lastSun 2:00 0 S
2474 Rule NT_YK 1980 1986 - Apr lastSun 2:00 1:00 D
2475 Rule NT_YK 1980 2006 - Oct lastSun 2:00 0 S
2476 Rule NT_YK 1987 2006 - Apr Sun>=1 2:00 1:00 D
2477 # Zone NAME STDOFF RULES FORMAT [UNTIL]
2479 Zone 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
2484 # formerly Frobisher Bay
2485 Zone 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
2490 Zone 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
2497 Zone 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
2501 # aka Iqaluktuuttiaq
2502 Zone 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
2508 Zone America/Yellowknife 0 - -00 1935 # Yellowknife founded?
2509 -7:00 NT_YK M%sT 1980
2511 Zone 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
2515 Zone 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
2520 Zone 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
2527 ###############################################################################
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
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.
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.
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.
2554 # ------------- Begin Forwarded Message -------------
2556 # I finally got my hands on the Official Presidential Decree that sets up the
2557 # rules for the DST changes. The rules are:
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)
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:
2570 # 3. The rest of the year, the times are as follows:
2575 # The Decree was published in Mexico's Official Newspaper on January 4th.
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
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).
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.
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
2600 # From Gwillim Law (2001-01-19):
2601 # <http://www.reforma.com/negocios_y_dinero/articulo/064481/> ... says
2603 # January 17, 2000 - The Energy Secretary, Ernesto Martens, announced
2604 # that Summer Time will be reduced from seven to five months, starting
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.
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.
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).
2624 # From Paul Eggert (2001-03-03):
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.
2635 # For now we'll assume that the Federal District will bow to federal rules.
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)
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.
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.
2664 # From Steffen Thorsen (2009-12-28):
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
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)
2680 # There is also a list of the votes here:
2681 # http://gaceta.diputados.gob.mx/Gaceta/61/2009/dic/V2-101209.html
2684 # https://www.timeanddate.com/news/time/north-mexico-dst-change.html
2686 # From Arthur David Olson (2010-01-20):
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.
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.
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."
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
2719 # Also, the new zone will not use DST.
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
2735 # 5- The islands, reefs and keys shall take their timezone from the
2736 # longitude they are located at.
2738 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
2739 Rule Mexico 1939 only - Feb 5 0:00 1:00 D
2740 Rule Mexico 1939 only - Jun 25 0:00 0 S
2741 Rule Mexico 1940 only - Dec 9 0:00 1:00 D
2742 Rule Mexico 1941 only - Apr 1 0:00 0 S
2743 Rule Mexico 1943 only - Dec 16 0:00 1:00 W # War
2744 Rule Mexico 1944 only - May 1 0:00 0 S
2745 Rule Mexico 1950 only - Feb 12 0:00 1:00 D
2746 Rule Mexico 1950 only - Jul 30 0:00 0 S
2747 Rule Mexico 1996 2000 - Apr Sun>=1 2:00 1:00 D
2748 Rule Mexico 1996 2000 - Oct lastSun 2:00 0 S
2749 Rule Mexico 2001 only - May Sun>=1 2:00 1:00 D
2750 Rule Mexico 2001 only - Sep lastSun 2:00 0 S
2751 Rule Mexico 2002 max - Apr Sun>=1 2:00 1:00 D
2752 Rule Mexico 2002 max - Oct lastSun 2:00 0 S
2753 # Zone NAME STDOFF RULES FORMAT [UNTIL]
2754 # Quintana Roo; represented by Cancún
2755 Zone 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
2760 # Campeche, Yucatán; represented by Mérida
2761 Zone 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
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,
2774 # http://www.eluniversal.com.mx/articulo/estados/2016/03/12/inicia-manana-horario-de-verano-en-zona-fronteriza
2775 Zone America/Matamoros -6:40:00 - LMT 1921 Dec 31 23:20:00
2778 -6:00 Mexico C%sT 2010
2780 # Durango; Coahuila, Nuevo León, Tamaulipas (away from US border)
2781 Zone America/Monterrey -6:41:16 - LMT 1921 Dec 31 23:18:44
2786 Zone 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
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.)
2799 Zone 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
2806 -6:00 Mexico C%sT 1998
2807 -6:00 - CST 1998 Apr Sun>=1 3:00
2808 -7:00 Mexico M%sT 2010
2810 # Chihuahua (away from US border)
2811 Zone 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
2818 -6:00 Mexico C%sT 1998
2819 -6:00 - CST 1998 Apr Sun>=1 3:00
2822 Zone 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
2831 -7:00 Mexico M%sT 1999
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).
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
2844 # Bahía de Banderas homologa su horario con el del Centro del
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
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
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
2856 # Baja California Sur, Nayarit, Sinaloa
2858 # From Arthur David Olson (2010-05-01):
2859 # Use "Bahia_Banderas" to keep the name to fourteen characters.
2862 Zone 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
2874 Zone 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
2883 -7:00 Mexico M%sT 2010 Apr 4 2:00
2887 Zone America/Tijuana -7:48:04 - LMT 1922 Jan 1 0:11:56
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
2902 -8:00 Mexico P%sT 2001
2903 -8:00 US P%sT 2002 Feb 20
2904 -8:00 Mexico P%sT 2010
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.
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.
2928 ###############################################################################
2931 # Antigua and Barbuda
2932 # See America/Port_of_Spain.
2936 # For 1899 Milne gives -5:09:29.5; round that.
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
2943 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
2944 Rule Bahamas 1964 1975 - Oct lastSun 2:00 0 S
2945 Rule Bahamas 1964 1975 - Apr lastSun 2:00 1:00 D
2946 # Zone NAME STDOFF RULES FORMAT [UNTIL]
2947 Zone America/Nassau -5:09:30 - LMT 1912 Mar 2
2948 -5:00 Bahamas E%sT 1976
2953 # For 1899 Milne gives -3:58:29.2; round that.
2955 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
2956 Rule Barb 1977 only - Jun 12 2:00 1:00 D
2957 Rule Barb 1977 1978 - Oct Sun>=1 2:00 0 S
2958 Rule Barb 1978 1980 - Apr Sun>=15 2:00 1:00 D
2959 Rule Barb 1979 only - Sep 30 2:00 0 S
2960 Rule Barb 1980 only - Sep 25 2:00 0 S
2961 # Zone NAME STDOFF RULES FORMAT [UNTIL]
2962 Zone America/Barbados -3:58:29 - LMT 1924 # Bridgetown
2963 -3:58:29 - BMT 1932 # Bridgetown Mean Time
2967 # Whitman entirely disagrees with Shanks; go with Shanks & Pottenger.
2968 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
2969 Rule Belize 1918 1942 - Oct Sun>=2 0:00 0:30 -0530
2970 Rule Belize 1919 1943 - Feb Sun>=9 0:00 0 CST
2971 Rule Belize 1973 only - Dec 5 0:00 1:00 CDT
2972 Rule Belize 1974 only - Feb 9 0:00 0 CST
2973 Rule Belize 1982 only - Dec 18 0:00 1:00 CDT
2974 Rule Belize 1983 only - Feb 12 0:00 0 CST
2975 # Zone NAME STDOFF RULES FORMAT [UNTIL]
2976 Zone America/Belize -5:52:48 - LMT 1912 Apr
2981 # For 1899 Milne gives -4:19:18.3 as the meridian of the clock tower,
2982 # Bermuda dockyard, Ireland I; round that.
2984 # From Dan Jones, reporting in The Royal Gazette (2006-06-26):
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
2992 # Zone NAME STDOFF RULES FORMAT [UNTIL]
2993 Zone 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
2999 # See America/Panama.
3003 # Milne gives -5:36:13.3 as San José mean time; round to nearest.
3005 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
3006 Rule CR 1979 1980 - Feb lastSun 0:00 1:00 D
3007 Rule CR 1979 1980 - Jun Sun>=1 0:00 0 S
3008 Rule 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.
3011 Rule CR 1991 only - Jul 1 0:00 0 S
3012 Rule 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]
3015 Zone America/Costa_Rica -5:36:13 - LMT 1890 # San José
3016 -5:36:13 - SJMT 1921 Jan 15 # San José Mean Time
3019 # no information; probably like America/Costa_Rica
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.
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.)
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
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.
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
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....
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.
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.
3076 # He supplied these references:
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
3081 # From Alex Krivenyshev (2007-10-25):
3082 # Here is also article from Granma (Cuba):
3084 # Regirá el Horario Normal desde el próximo domingo 28 de octubre
3085 # http://www.granma.cubaweb.cu/2007/10/24/nacional/artic07.html
3087 # http://www.worldtimezone.com/dst_news/dst_news_cuba03.html
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.
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
3102 # Some more background information is posted here:
3103 # https://www.timeanddate.com/news/time/cuba-starts-dst-march-16.html
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.
3113 # http://www.radiohc.cu/espanol/noticias/mar07/11mar/hor.htm
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
3120 # Basically as expected after Steffen Thorsen's information, the change
3121 # will take place midnight between Saturday and Sunday.
3123 # From Arthur David Olson (2008-03-12):
3124 # Assume Sun>=15 (third Sunday) going forward.
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.
3131 # http://www.worldtimezone.com/dst_news/dst_news_cuba05.html
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.
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
3147 # http://granma.co.cu/2011/03/08/nacional/artic01.html
3150 # https://www.timeanddate.com/news/time/cuba-starts-dst-2011.html
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.
3156 # One source (Spanish)
3157 # http://www.radioangulo.cu/noticias/cuba/17105-cuba-restablecera-el-horario-del-meridiano-de-greenwich.html
3160 # https://www.timeanddate.com/news/time/cuba-time-changes-2011.html
3162 # From Steffen Thorsen (2012-03-01)
3163 # According to Radio Reloj, Cuba will start DST on Midnight between March
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
3170 # https://www.timeanddate.com/news/time/cuba-starts-dst-2012.html
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.
3179 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
3180 Rule Cuba 1928 only - Jun 10 0:00 1:00 D
3181 Rule Cuba 1928 only - Oct 10 0:00 0 S
3182 Rule Cuba 1940 1942 - Jun Sun>=1 0:00 1:00 D
3183 Rule Cuba 1940 1942 - Sep Sun>=1 0:00 0 S
3184 Rule Cuba 1945 1946 - Jun Sun>=1 0:00 1:00 D
3185 Rule Cuba 1945 1946 - Sep Sun>=1 0:00 0 S
3186 Rule Cuba 1965 only - Jun 1 0:00 1:00 D
3187 Rule Cuba 1965 only - Sep 30 0:00 0 S
3188 Rule Cuba 1966 only - May 29 0:00 1:00 D
3189 Rule Cuba 1966 only - Oct 2 0:00 0 S
3190 Rule Cuba 1967 only - Apr 8 0:00 1:00 D
3191 Rule Cuba 1967 1968 - Sep Sun>=8 0:00 0 S
3192 Rule Cuba 1968 only - Apr 14 0:00 1:00 D
3193 Rule Cuba 1969 1977 - Apr lastSun 0:00 1:00 D
3194 Rule Cuba 1969 1971 - Oct lastSun 0:00 0 S
3195 Rule Cuba 1972 1974 - Oct 8 0:00 0 S
3196 Rule Cuba 1975 1977 - Oct lastSun 0:00 0 S
3197 Rule Cuba 1978 only - May 7 0:00 1:00 D
3198 Rule Cuba 1978 1990 - Oct Sun>=8 0:00 0 S
3199 Rule Cuba 1979 1980 - Mar Sun>=15 0:00 1:00 D
3200 Rule Cuba 1981 1985 - May Sun>=5 0:00 1:00 D
3201 Rule Cuba 1986 1989 - Mar Sun>=14 0:00 1:00 D
3202 Rule Cuba 1990 1997 - Apr Sun>=1 0:00 1:00 D
3203 Rule Cuba 1991 1995 - Oct Sun>=8 0:00s 0 S
3204 Rule Cuba 1996 only - Oct 6 0:00s 0 S
3205 Rule Cuba 1997 only - Oct 12 0:00s 0 S
3206 Rule Cuba 1998 1999 - Mar lastSun 0:00s 1:00 D
3207 Rule Cuba 1998 2003 - Oct lastSun 0:00s 0 S
3208 Rule Cuba 2000 2003 - Apr Sun>=1 0:00s 1:00 D
3209 Rule Cuba 2004 only - Mar lastSun 0:00s 1:00 D
3210 Rule Cuba 2006 2010 - Oct lastSun 0:00s 0 S
3211 Rule Cuba 2007 only - Mar Sun>=8 0:00s 1:00 D
3212 Rule Cuba 2008 only - Mar Sun>=15 0:00s 1:00 D
3213 Rule Cuba 2009 2010 - Mar Sun>=8 0:00s 1:00 D
3214 Rule Cuba 2011 only - Mar Sun>=15 0:00s 1:00 D
3215 Rule Cuba 2011 only - Nov 13 0:00s 0 S
3216 Rule Cuba 2012 only - Apr 1 0:00s 1:00 D
3217 Rule Cuba 2012 max - Nov Sun>=1 0:00s 0 S
3218 Rule Cuba 2013 max - Mar Sun>=8 0:00s 1:00 D
3220 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3221 Zone America/Havana -5:29:28 - LMT 1890
3222 -5:29:36 - HMT 1925 Jul 19 12:00 # Havana MT
3226 # See America/Port_of_Spain.
3228 # Dominican Republic
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
3235 # From Paul Eggert (2000-12-04):
3236 # That URL (2000-10-26, in Spanish) says they planned to use US-style DST.
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.
3248 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
3249 Rule DR 1966 only - Oct 30 0:00 1:00 EDT
3250 Rule DR 1967 only - Feb 28 0:00 0 EST
3251 Rule DR 1969 1973 - Oct lastSun 0:00 0:30 -0430
3252 Rule DR 1970 only - Feb 21 0:00 0 EST
3253 Rule DR 1971 only - Jan 20 0:00 0 EST
3254 Rule DR 1972 1974 - Jan 21 0:00 0 EST
3255 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3256 Zone 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
3265 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
3266 Rule Salv 1987 1988 - May Sun>=1 0:00 1:00 D
3267 Rule 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]
3271 Zone America/El_Salvador -5:56:48 - LMT 1921 # San Salvador
3277 # St Martin (French part)
3278 # See America/Port_of_Spain.
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
3294 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
3295 Rule Guat 1973 only - Nov 25 0:00 1:00 D
3296 Rule Guat 1974 only - Feb 24 0:00 0 S
3297 Rule Guat 1983 only - May 21 0:00 1:00 D
3298 Rule Guat 1983 only - Sep 22 0:00 0 S
3299 Rule Guat 1991 only - Mar 23 0:00 1:00 D
3300 Rule Guat 1991 only - Sep 7 0:00 0 S
3301 Rule Guat 2006 only - Apr 30 0:00 1:00 D
3302 Rule Guat 2006 only - Oct 1 0:00 0 S
3303 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3304 Zone America/Guatemala -6:02:04 - LMT 1918 Oct 5
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:
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.
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
3325 # "Port-au-Prince, March 31, 2005"
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).
3333 # I have found this article about it (in French):
3334 # http://www.haitipressnetwork.com/news.cfm?articleID=7612
3336 # The reason seems to be an energy crisis.
3338 # From Stephen Colebourne (2007-02-22):
3339 # Some IATA info: Haiti won't be having DST in 2007.
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.
3346 # http://www.alterpresse.org/spip.php?article12510
3347 # http://radiovision2000haiti.net/home/?p=13253
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.
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...
3359 # http://radiovision2000haiti.net/public/haiti-avis-changement-dheure-dimanche/
3360 # http://www.canalplushaiti.net/?p=6714
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/
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
3375 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
3376 Rule Haiti 1983 only - May 8 0:00 1:00 D
3377 Rule Haiti 1984 1987 - Apr lastSun 0:00 1:00 D
3378 Rule 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.
3381 Rule Haiti 1988 1997 - Apr Sun>=1 1:00s 1:00 D
3382 Rule Haiti 1988 1997 - Oct lastSun 1:00s 0 S
3383 Rule Haiti 2005 2006 - Apr Sun>=1 0:00 1:00 D
3384 Rule Haiti 2005 2006 - Oct lastSun 0:00 0 S
3385 Rule Haiti 2012 2015 - Mar Sun>=8 2:00 1:00 D
3386 Rule Haiti 2012 2015 - Nov Sun>=1 2:00 0 S
3387 Rule Haiti 2017 max - Mar Sun>=8 2:00 1:00 D
3388 Rule Haiti 2017 max - Nov Sun>=1 2:00 0 S
3389 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3390 Zone America/Port-au-Prince -4:49:20 - LMT 1890
3391 -4:49 - PPMT 1917 Jan 24 12:00 # P-a-P MT
3395 # Shanks & Pottenger say 1921 Jan 1; go with Whitman's more precise Apr 1.
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.
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
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.
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
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....
3423 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
3424 Rule Hond 1987 1988 - May Sun>=1 0:00 1:00 D
3425 Rule Hond 1987 1988 - Sep lastSun 0:00 0 S
3426 Rule Hond 2006 only - May Sun>=1 0:00 1:00 D
3427 Rule Hond 2006 only - Aug Mon>=1 0:00 0 S
3428 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3429 Zone America/Tegucigalpa -5:48:52 - LMT 1921 Apr
3432 # Great Swan I ceded by US to Honduras in 1972
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.
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
3449 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3450 Zone America/Jamaica -5:07:10 - LMT 1890 # Kingston
3451 -5:07:10 - KMT 1912 Feb # Kingston Mean Time
3457 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3458 Zone 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
3465 # See America/Port_of_Spain.
3469 # This uses Shanks & Pottenger for times before 2005.
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
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....
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.
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
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.
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.
3514 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
3515 Rule Nic 1979 1980 - Mar Sun>=16 0:00 1:00 D
3516 Rule Nic 1979 1980 - Jun Mon>=23 0:00 0 S
3517 Rule Nic 2005 only - Apr 10 0:00 1:00 D
3518 Rule Nic 2005 only - Oct Sun>=1 0:00 0 S
3519 Rule Nic 2006 only - Apr 30 2:00 1:00 D
3520 Rule Nic 2006 only - Oct Sun>=1 1:00 0 S
3521 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3522 Zone 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
3533 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3534 Zone America/Panama -5:18:08 - LMT 1890
3535 -5:19:36 - CMT 1908 Apr 22 # Colón Mean Time
3537 Link America/Panama America/Cayman
3540 # There are too many San Juans elsewhere, so we'll use 'Puerto_Rico'.
3541 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3542 Zone America/Puerto_Rico -4:24:25 - LMT 1899 Mar 28 12:00 # San Juan
3543 -4:00 - AST 1942 May 3
3549 # See America/Port_of_Spain.
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]
3554 Zone America/Miquelon -3:44:40 - LMT 1911 May 15 # St Pierre
3555 -4:00 - AST 1980 May
3557 -3:00 Canada -03/-02
3559 # St Vincent and the Grenadines
3560 # See America/Port_of_Spain.
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.
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.
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
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
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/
3599 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3600 Zone America/Grand_Turk -4:44:32 - LMT 1890
3601 -5:07:10 - KMT 1912 Feb # Kingston Mean Time
3603 -5:00 US E%sT 2015 Nov Sun>=1 2:00
3604 -4:00 - AST 2018 Mar 11 3:00
3609 # See America/Port_of_Spain.
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