3 # This data is by no means authoritative; if you think you know better,
4 # go ahead and edit the file (and please send any changes to
5 # tz@elsie.nci.nih.gov for general use in the future).
7 # From Paul Eggert <eggert@twinsun.com> (November 18, 1993):
8 # A good source for time zone historical data outside the U.S. is
9 # Thomas G. Shanks, The International Atlas (3rd edition),
10 # San Diego: ACS Publications, Inc. (1991).
11 # Except where otherwise noted, it is the source for the data below.
13 # I invented the abbreviations marked `*' in the following table;
14 # the rest are from earlier versions of this file, or from other sources.
15 # Some of these are just plausible excuses for common English abbreviations.
16 # Corrections are welcome!
19 # -2:00 FST FDT Fernando de Noronha
20 # -3:00 EST EDT Eastern South America (conflicts with -5:00)
21 # -4:00 AST ADT Andes*, Antilles*, Asuncion*, Atlantic
22 # -4:00 CST CDT Chile (conflicts with -6:00)
23 # -4:00 WST WDT Western Brazil
24 # -5:00 AST ADT Acre (conflicts with -4:00)
25 # -5:00 EST EDT Eastern, Ecuador*
26 # -6:00 CST CDT Archipelago of Columbus*, Central
27 # -7:00 MST MDT Mataveri*, Mountain
29 # See the `africa' file for Zone naming conventions.
32 # From Official Airline Guide - Worldwide Edition (1987). Countries not
33 # listed here do not observe DST, according to the OAG. Time zone names
34 # are pure inventions, and none are supplied for countries not observing
35 # DST; updates from natives would be appreciated. The times that DST
36 # starts and ends are based on the assumption that they switch a 2AM just
37 # as everybody else does.
39 ###############################################################################
41 ###############################################################################
45 # From Bob Devine (January 28, 1988):
46 # Argentina: first Sunday in October to first Sunday in April since 1976.
47 # Double Summer time from 1969 to 1974. Switches at midnight.
49 # From U. S. Naval Observatory (January 19, 19889):
50 # ARGENTINA 3 H BEHIND UTC
52 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
53 Rule Arg 1930 only - Dec 1 0:00 1:00 D
54 Rule Arg 1931 only - Apr 1 0:00 0 S
55 Rule Arg 1931 only - Oct 15 0:00 1:00 D
56 Rule Arg 1932 1940 - Mar 1 0:00 0 S
57 Rule Arg 1932 1939 - Nov 1 0:00 1:00 D
58 Rule Arg 1940 only - Jul 1 0:00 1:00 D
59 Rule Arg 1941 only - Jun 15 0:00 0 S
60 Rule Arg 1941 only - Oct 15 0:00 1:00 D
61 Rule Arg 1943 only - Aug 1 0:00 0 S
62 Rule Arg 1943 only - Oct 15 0:00 1:00 D
63 Rule Arg 1946 only - Mar 1 0:00 0 S
64 Rule Arg 1946 only - Oct 1 0:00 1:00 D
65 Rule Arg 1963 only - Oct 1 0:00 0 S
66 Rule Arg 1963 only - Dec 15 0:00 1:00 D
67 Rule Arg 1964 1966 - Mar 1 0:00 0 S
68 Rule Arg 1964 1966 - Oct 15 0:00 1:00 D
69 Rule Arg 1967 only - Apr 1 0:00 0 S
70 Rule Arg 1967 1968 - Oct Sun<=7 0:00 1:00 D
71 Rule Arg 1968 1969 - Apr Sun<=7 0:00 0 S
72 Rule Arg 1974 only - Jan 23 0:00 1:00 D
73 Rule Arg 1974 only - May 1 0:00 0 S
74 Rule Arg 1974 1976 - Oct Sun<=7 0:00 1:00 D
75 Rule Arg 1975 1977 - Apr Sun<=7 0:00 0 S
76 Rule Arg 1985 only - Nov 2 0:00 1:00 D
77 Rule Arg 1986 only - Mar 14 0:00 0 S
78 Rule Arg 1986 1987 - Oct 25 0:00 1:00 D
79 Rule Arg 1987 only - Feb 13 0:00 0 S
80 Rule Arg 1988 only - Feb 7 0:00 0 S
81 Rule Arg 1988 only - Dec 1 0:00 1:00 D
82 Rule Arg 1989 only - Mar 16 0:00 0 S
83 Rule Arg 1989 only - Oct 15 0:00 1:00 D
84 Rule Arg 1990 only - Mar 4 0:00 0 S
85 # _The Economist_ (8 Jan 1994, p 42) reports that Argentina
86 # had DST in 1991-2 and 1992-3, but not in 1990-1 or in 1993-4.
87 # It has something to do with electricity companies meeting demand in summer.
88 # We don't know the 1991-3 transition times, unfortunately.
89 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
90 Zone America/Buenos_Aires -3:53:48 - LMT 1894 Nov
91 -4:17 - CMT 1920 May # Cordoba Mean Time
93 -4:00 Arg A%sT 1969 Oct 5
97 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
98 Zone America/La_Paz -4:32:36 - LMT 1890
99 -4:33 - LPMT 1931 Oct 15 # La Paz Mean Time
100 -4:33 1:00 LPDT 1932 Mar 21
106 # The OAG lists October 25, 1987 and February 12, 1988 as the starting and
107 # ending dates, giving them as "estimated date(s) based on previous year". We
108 # infer a rule here from one example, always a dangerous practice.... Yes,
109 # they really do switch on Saturday, according to the OAG.
110 # "Brazil/Acre" is for the Territory of Acre; "Brazil/DeNoronha" is for
111 # Fernando De Noronha.
113 # From Bob Devine (January 28, 1988):
114 # The only information I found is that there was no DST up to 1985.
115 # But there was some before 1952!
117 # From U. S. Naval Observatory (January 16, 1989):
118 # BRAZIL WEST 5 H BEHIND UTC TERRITORY OF ACRE
119 # BRAZIL WEST 4 H BEHIND UTC ACRE OCT 23, '88-FEB 11,
120 # BRAZIL '89 (ESTIMATED)
121 # BRAZIL CENTRAL 4 H BEHIND UTC MANAUS
122 # BRAZIL CENTRAL 3 H BEHIND UTC MANAUS OCT 23, '88-FEB 11,
123 # BRAZIL CENTRAL '89 (ESTIMATED)
124 # BRAZIL EAST 3 H BEHIND UTC COASTAL STATES, RIO, SAO
125 # BRAZIL EAST PAULO, BRASILIA
126 # BRAZIL EAST 2 H BEHIND UTC COASTAL STATES, RIO, SAO
127 # BRAZIL PAULO, BRASILIA OCT 23,
128 # BRAZIL '88-FEB 11, '89
130 # BRAZIL 2 H BEHIND UTC ATLANTIC ISLANDS, FERNANDO
132 # BRAZIL 1 H BEHIND UTC OCT 23, '88-FEB 11, '89
134 # BRAZIL 3 H BEHIND UTC FOR MOST MAJOR AIRPORTS.
136 # From Paul Eggert <eggert@twinsun.com> (November 18, 1993):
137 # The mayor of Rio recently attempted to change the time zone rules
138 # just in his city, in order to leave more summer time for the tourist trade.
139 # The rule change lasted only part of the day;
140 # the federal government refused to follow the city's rules, and business
141 # was in a chaos, so the mayor backed down that afternoon.
142 # Shanks claims Acre stopped observing DST after 1988 Feb 7, but it
143 # could just be that his table ran out of room. We're extrapolating
144 # about time zone changes after 1990 Feb 11.
146 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
147 Rule Brazil 1914 only - Jan 1 0:00 0 S
148 Rule Brazil 1931 only - Oct 3 11:00 1 D
149 Rule Brazil 1932 1933 - Apr 1 0:00 0 S
150 Rule Brazil 1932 only - Oct 3 0:00 1 D
151 Rule Brazil 1949 1952 - Dec 1 0:00 1 D
152 Rule Brazil 1950 only - Apr 16 0:00 0 S
153 Rule Brazil 1951 1953 - Apr 1 0:00 0 S
154 Rule Brazil 1963 only - Dec 9 0:00 1 D
155 Rule Brazil 1964 only - Mar 1 0:00 0 S
156 Rule Brazil 1965 only - Jan 31 0:00 1 D
157 Rule Brazil 1965 only - Apr 1 0:00 0 S
158 Rule Brazil 1965 only - Dec 1 0:00 1 D
159 Rule Brazil 1966 1968 - Mar 1 0:00 0 S
160 Rule Brazil 1966 1967 - Nov 1 0:00 1 D
161 Rule Brazil 1985 only - Nov 2 0:00 1 D
162 Rule Brazil 1986 only - Mar 15 0:00 0 S
163 Rule Brazil 1986 1987 - Oct Sat<=28 0:00 1 D
164 Rule Brazil 1987 only - Feb 14 0:00 0 S
165 Rule Brazil 1988 only - Feb 7 0:00 0 S
166 Rule Brazil 1989 only - Jan 22 0:00 0 S
167 Rule Brazil 1988 max - Oct Sun>=15 0:00 1 D
168 Rule Brazil 1990 max - Feb Sun>=8 0:00 0 S
169 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
170 Zone America/Noronha -2:09:40 - LMT 1914
171 -2:00 - FST 1963 Dec 9
173 Zone America/Sao_Paulo -3:06:28 - LMT 1914
175 Zone America/Manaus -4:00:04 - LMT 1914
176 -4:00 - WST 1963 Dec 9
178 # Rio_Branco is too ambiguous, since there's a Rio Branco in Uruguay too.
179 Zone America/Porto_Acre -4:31:12 - LMT 1914
180 -5:00 - AST 1963 Dec 9
183 # Martin Vaz and Trinidade are like America/Noronha.
189 # The OAG lists October 11, 1987 and March 12, 1988 as the starting and
190 # ending dates, giving them as "estimated date(s) based on previous year."
192 # From Bob Devine (January 28, 1988):
193 # Chile has had 2nd Sunday in October to 2nd Sunday in March DST since 1977.
194 # Switch is at midnight. OAG is right.
196 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
197 Rule Chile 1918 only - Sep 1 0:00 1:00 D
198 Rule Chile 1919 only - Jul 2 0:00 0 S
199 Rule Chile 1927 1931 - Sep 1 0:00 1:00 D
200 Rule Chile 1928 1932 - Apr 1 0:00 0 S
201 Rule Chile 1969 max - Oct Sun>=8 0:00 1:00 D
202 Rule Chile 1970 max - Mar Sun>=8 0:00 0 S
203 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
204 Zone America/Santiago -4:42:40 - LMT 1890
205 -4:43 - SMT 1910 # Santiago Mean Time
206 -5:00 Chile C%sT 1932 Sep
208 Zone Pacific/Easter -7:17:28 - LMT 1890 # Mataveri
209 -7:17 - MMT 1932 Sep # Mataveri Mean Time
210 -7:00 Chile M%sT 1982 Mar 14
213 # Whitman says Juan Fernandez Is are like America/Santiago.
214 # San Ambrosio, San Felix
215 # no information; probably like America/Santiago
219 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
220 Zone America/Bogota -4:56:20 - LMT 1884 Mar 13
221 -4:56 - BMT 1914 Nov 23 # Bogota Mean Time
223 # Malpelo, Providencia, San Andres
224 # no information; probably like America/Bogota
227 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
228 Zone America/Curacao -4:35:44 - LMT 1912 Feb 12 # Willemstad
229 -4:30 - NAST 1965 # Netherlands Antilles
233 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
234 Zone America/Guayaquil -5:19:20 - LMT 1890
235 -5:14 - QMT 1931 # Quito Mean Time
237 Zone Pacific/Galapagos -5:58:24 - LMT 1931 # Puerto Baquerizo Moreno
242 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
243 Rule Falk 1912 only - Mar 12 0:00 0 S
244 Rule Falk 1937 1938 - Sep lastSun 0:00 1:00 D
245 Rule Falk 1938 1942 - Mar Sun>=19 0:00 0 S
246 Rule Falk 1939 only - Oct 1 0:00 1:00 D
247 Rule Falk 1940 1942 - Sep lastSun 0:00 1:00 D
248 Rule Falk 1943 only - Jan 1 0:00 0 S
249 Rule Falk 1983 only - Sep lastSun 0:00 1:00 D
250 Rule Falk 1984 1985 - Apr lastSun 0:00 0 S
251 Rule Falk 1984 only - Sep 16 0:00 1:00 D
252 Rule Falk 1985 max - Sep Sun>=9 0:00 1:00 D
253 Rule Falk 1986 max - Apr Sun>=16 0:00 0 S
254 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
255 Zone Atlantic/Stanley -3:51:24 - LMT 1890
256 -3:51 - SMT 1912 Mar 12 # Stanley Mean Time
257 -4:00 Falk A%sT 1983 May
258 -3:00 Falk E%sT 1985 Sep 15
262 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
263 Zone America/Cayenne -3:29:20 - LMT 1911 Jul
268 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
269 Zone America/Guyana -3:52:40 - LMT 1915 Mar # Georgetown
270 -3:45 - BGST 1975 Jul 31 # British Guiana ST
276 # From Bob Devine (January 28, 1988):
277 # Paraguay: First day in October to last in March. Midnight switch??
280 # From U. S. Naval Observatory (January 19, 1989):
281 # PARAGUAY 4 H BEHIND UTC
282 # PARAGUAY 3 H BEHIND UTC OCT 1, '88-MAR 31, '89
284 # From Shanks (1991):
285 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
286 Rule Para 1974 only - Apr 1 0:00 0 S
287 Rule Para 1975 1978 - Oct 1 0:00 1:00 D
288 Rule Para 1975 1978 - Mar 1 0:00 0 S
289 # Shanks says 1979 was all DST.
290 Rule Para 1980 max - Apr 1 0:00 0 S
291 Rule Para 1980 1988 - Oct 1 0:00 1:00 D
292 Rule Para 1989 only - Oct 22 0:00 1:00 D
293 Rule Para 1990 max - Oct 1 0:00 1:00 D
294 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
295 Zone America/Asuncion -3:50:40 - LMT 1890
296 -3:51 - AMT 1931 Oct 10 # Asuncion Mean Time
302 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
303 Rule Peru 1908 only - Jul 28 0:00 0 S
304 Rule Peru 1938 only - Jan 1 0:00 1:00 D
305 Rule Peru 1938 only - Apr 1 0:00 0 S
306 Rule Peru 1938 1939 - Sep lastSun 0:00 1:00 D
307 Rule Peru 1939 1940 - Mar Sun>=24 0:00 0 S
308 Rule Peru 1987 only - Jan 1 0:00 1:00 D
309 Rule Peru 1987 only - Apr 1 0:00 0 S
310 Rule Peru 1990 only - Jan 1 0:00 1:00 D
311 Rule Peru 1990 only - Apr 1 0:00 0 S
312 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
313 Zone America/Lima -5:08:12 - LMT 1890
314 -5:09 - LMT 1908 Jul 28
318 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
319 Zone Atlantic/South_Georgia -2:26:08 - LMT 1890 # Grytviken
326 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
327 Zone America/Paramaribo -3:40:40 - LMT 1911
328 -3:40:52 - PMT 1935 # Paramaribo Mean Time
329 -3:40:36 - PMT 1945 Oct # The capital moved?
330 -3:30 - DGST 1984 Oct # Dutch Guiana Std Time
333 # Trinidad and Tobago
334 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
335 Zone America/Port_of_Spain -4:06:04 - LMT 1912 Mar 2
339 # From Paul Eggert <eggert@twinsun.com> (November 18, 1993):
340 # Uruguay wins the prize for the strangest peacetime manipulation of the rules.
341 # Your guess is as good as mine for what happened after 1989.
342 # From Shanks (1991):
343 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
344 Rule Uruguay 1920 only - May 1 0:00 0 S
345 # Whitman gives 1923 Oct 1; go with Shanks.
346 Rule Uruguay 1923 only - Oct 2 0:00 0:30 HD
347 Rule Uruguay 1924 1926 - Apr 1 0:00 0 S
348 Rule Uruguay 1924 1925 - Oct 1 0:00 0:30 HD
349 Rule Uruguay 1933 1935 - Oct lastSun 0:00 0:30 HD
350 # Shanks gives 1935 Apr 1 0:00 and 1936 Mar 30 0:00; go with Whitman.
351 Rule Uruguay 1934 1936 - Mar Sat>=25 23:30s 0 S
352 Rule Uruguay 1936 only - Nov 1 0:00 0:30 HD
353 Rule Uruguay 1937 1941 - Mar lastSun 0:00 0 S
354 # Whitman gives 1937 Oct 3; go with Shanks.
355 Rule Uruguay 1937 1940 - Oct lastSun 0:00 0:30 HD
356 # Whitman gives 1941 Oct 24 - 1942 Mar 27, 1942 Dec 14 - 1943 Apr 13,
357 # and 1943 Apr 13 ``to present time''; go with Shanks.
358 Rule Uruguay 1941 only - Aug 1 0:00 0 S
359 Rule Uruguay 1942 only - Jan 1 0:00 0:30 HD
360 Rule Uruguay 1942 only - Dec 14 0:00 1:00 D
361 Rule Uruguay 1943 only - Mar 14 0:00 0 S
362 Rule Uruguay 1959 only - May 24 0:00 1:00 D
363 Rule Uruguay 1959 only - Nov 15 0:00 0 S
364 Rule Uruguay 1960 only - Jan 17 0:00 1:00 D
365 Rule Uruguay 1960 only - Mar 6 0:00 0 S
366 Rule Uruguay 1965 1967 - Apr Sun>=1 0:00 1:00 D
367 Rule Uruguay 1965 only - Sep 26 0:00 0 S
368 Rule Uruguay 1966 1967 - Oct 31 0:00 0 S
369 Rule Uruguay 1968 1970 - May 27 0:00 0:30 HD
370 Rule Uruguay 1968 1970 - Dec 2 0:00 0 S
371 Rule Uruguay 1972 only - Apr 24 0:00 1:00 D
372 Rule Uruguay 1972 only - Aug 15 0:00 0 S
373 Rule Uruguay 1974 only - Mar 10 0:00 0:30 HD
374 Rule Uruguay 1974 only - Dec 22 0:00 1:00 D
375 Rule Uruguay 1976 only - Oct 1 0:00 0 S
376 Rule Uruguay 1977 only - Dec 4 0:00 1:00 D
377 Rule Uruguay 1978 only - Apr 1 0:00 0 S
378 Rule Uruguay 1979 only - Oct 1 0:00 1:00 D
379 Rule Uruguay 1980 only - May 1 0:00 0 S
380 Rule Uruguay 1987 only - Dec 14 0:00 1:00 D
381 Rule Uruguay 1988 only - Mar 14 0:00 0 S
382 Rule Uruguay 1988 only - Dec 11 0:00 1:00 D
383 Rule Uruguay 1989 only - Mar 12 0:00 0 S
384 Rule Uruguay 1989 only - Oct 29 0:00 1:00 D
385 Rule Uruguay 1990 only - Mar 4 0:00 0 S
386 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
387 Zone America/Montevideo -3:44:44 - LMT 1898 Jun 28
388 -3:45 - MMT 1920 May 1 # Montevideo MT
389 -3:30 Uruguay U%sT 1942 Dec 14 # Uruguay ST
393 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
394 Zone America/Caracas -4:27:44 - LMT 1890
395 -4:28 - CMT 1912 Feb 12 # Caracas Mean Time
396 -4:30 - VZT 1965 # Venezuela Time