1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
|
# @(#)southamerica 7.49
# This data is by no means authoritative; if you think you know better,
# go ahead and edit the file (and please send any changes to
# tz@elsie.nci.nih.gov for general use in the future).
# From Paul Eggert <eggert@twinsun.com> (1999-07-07):
# A good source for time zone historical data outside the U.S. is
# Thomas G. Shanks, The International Atlas (5th edition),
# San Diego: ACS Publications, Inc. (1999).
#
# Gwillim Law writes that a good source
# for recent time zone data is the International Air Transport
# Association's Standard Schedules Information Manual (IATA SSIM),
# published semiannually. Law sent in several helpful summaries
# of the IATA's data after 1990.
#
# Except where otherwise noted, Shanks is the source for entries through 1990,
# and IATA SSIM is the source for entries after 1990.
#
# Earlier editions of these tables used the North American style (e.g. ARST and
# ARDT for Argentine Standard and Daylight Time), but the following quote
# suggests that it's better to use European style (e.g. ART and ARST).
# I suggest the use of _Summer time_ instead of the more cumbersome
# _daylight-saving time_. _Summer time_ seems to be in general use
# in Europe and South America.
# -- E O Cutler, _New York Times_ (1937-02-14), quoted in
# H L Mencken, _The American Language: Supplement I_ (1960), p 466
#
# Earlier editions of these tables also used the North American style
# for time zones in Brazil, but this was incorrect, as Brazilians say
# "summer time". Reinaldo Goulart, a Sao Paulo businessman active in
# the railroad sector, writes (1999-07-06):
# The subject of time zones is currently a matter of discussion/debate in
# Brazil. Let's say that "the Brasilia time" is considered the
# "official time" because Brasilia is the capital city.
# The other three time zones are called "Brasilia time "minus one" or
# "plus one" or "plus two". As far as I know there is no such
# name/designation as "Eastern Time" or "Central Time".
# So I invented the following (English-language) abbreviations for now.
# Corrections are welcome!
# std dst
# -2:00 FNT FNST Fernando de Noronha
# -3:00 BRT BRST Brasilia
# -4:00 AMT AMST Amazon
# -5:00 ACT ACST Acre
###############################################################################
###############################################################################
# Argentina
# From Bob Devine (1988-01-28):
# Argentina: first Sunday in October to first Sunday in April since 1976.
# Double Summer time from 1969 to 1974. Switches at midnight.
# From U. S. Naval Observatory (1988-01-199):
# ARGENTINA 3 H BEHIND UTC
# From Hernan G. Otero <hernan@isoft.com.ar> (1995-06-26):
# I am sending modifications to the Argentine time zone table...
# AR was chosen because they are the ISO letters that represent Argentina.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Arg 1930 only - Dec 1 0:00 1:00 S
Rule Arg 1931 only - Apr 1 0:00 0 -
Rule Arg 1931 only - Oct 15 0:00 1:00 S
Rule Arg 1932 1940 - Mar 1 0:00 0 -
Rule Arg 1932 1939 - Nov 1 0:00 1:00 S
Rule Arg 1940 only - Jul 1 0:00 1:00 S
Rule Arg 1941 only - Jun 15 0:00 0 -
Rule Arg 1941 only - Oct 15 0:00 1:00 S
Rule Arg 1943 only - Aug 1 0:00 0 -
Rule Arg 1943 only - Oct 15 0:00 1:00 S
Rule Arg 1946 only - Mar 1 0:00 0 -
Rule Arg 1946 only - Oct 1 0:00 1:00 S
Rule Arg 1963 only - Oct 1 0:00 0 -
Rule Arg 1963 only - Dec 15 0:00 1:00 S
Rule Arg 1964 1966 - Mar 1 0:00 0 -
Rule Arg 1964 1966 - Oct 15 0:00 1:00 S
Rule Arg 1967 only - Apr 2 0:00 0 -
Rule Arg 1967 1968 - Oct Sun>=1 0:00 1:00 S
Rule Arg 1968 1969 - Apr Sun>=1 0:00 0 -
Rule Arg 1974 only - Jan 23 0:00 1:00 S
Rule Arg 1974 only - May 1 0:00 0 -
Rule Arg 1988 only - Dec 1 0:00 1:00 S
#
# From Hernan G. Otero <hernan@isoft.com.ar> (1995-06-26):
# These corrections were contributed by InterSoft Argentina S.A.,
# obtaining the data from the:
# Talleres de Hidrografia Naval Argentina
# (Argentine Naval Hydrography Institute)
#
# Shanks stops after 1992-03-01; go with Otero.
Rule Arg 1989 1993 - Mar Sun>=1 0:00 0 -
Rule Arg 1989 1992 - Oct Sun>=15 0:00 1:00 S
#
# From Hernan G. Otero <hernan@isoft.com.ar> (1995-06-26):
# From this moment on, the law that mandated the daylight saving
# time corrections was derogated and no more modifications
# to the time zones (for daylight saving) are now made.
#
# From Rives McDow (2000-01-10):
# On October 3, 1999, 0:00 local, Argentina implemented daylight savings time,
# which did not result in the switch of a time zone, as they stayed 9 hours
# from the International Date Line.
Rule Arg 1999 only - Oct Sun>=1 0:00 1:00 S
Rule Arg 2000 only - Mar Sun>=1 0:00 0 -
#
# From Peter Gradelski via Steffen Thorsen (2000-03-01):
# We just checked with our Sao Paulo office and they say the government of
# Argentina decided not to become one of the countries that go on or off DST.
# So Buenos Aires should be -3 hours from GMT at all times.
#
# From Fabian L. Arce Jofre <farcejofre@bigfoot.com> (2000-04-04):
# The law that claimed DST for Argentina was derogated by President Fernando
# de la Rua on March 2, 2000, because it would make people spend more energy
# in the winter time, rather than less. The change took effect on March 3.
#
# From Mariano Absatz (2001-06-06):
# one of the major newspapers here in Argentina said that the 1999
# Timezone Law (which never was effectively applied) will (would?) be
# in effect.... The article is at
# http://ar.clarin.com/diario/2001-06-06/e-01701.htm
# ... The Law itself is "Ley No 25155", sanctioned on 1999-08-25, enacted
# 1999-09-17, and published 1999-09-21. The official publication is at:
# http://www.boletin.jus.gov.ar/BON/Primera/1999/09-Septiembre/21/PDF/BO21-09-99LEG.PDF
# Regretfully, you have to subscribe (and pay) for the on-line version....
#
# (2001-06-12):
# the timezone for Argentina will not change next Sunday.
# Apparently it will do so on Sunday 24th....
# http://ar.clarin.com/diario/2001-06-12/s-03501.htm
#
# (2001-06-25):
# Last Friday (yes, the last working day before the date of the change), the
# Senate annulled the 1999 law that introduced the changes later postponed.
# http://www.clarin.com.ar/diario/2001-06-22/s-03601.htm
# It remains the vote of the Deputies..., but it will be the same....
# This kind of things had always been done this way in Argentina.
# We are still -03:00 all year round in all of the country.
#
#
# From Paul Eggert (2002-01-22):
# <a href="http://www.spicasc.net/horvera.html">
# Hora de verano para la Republica Argentina (2000-10-01)
# </a> says that standard time in Argentina from 1894-10-31
# to 1920-05-01 was -4:16:48.25. Go with this more-precise value
# over Shanks.
# Unless otherwise specified, data are from Shanks through 1992, from
# the IATA otherwise. As noted below, Shanks says that
# America/Cordoba split into 7 subregions during 1991/1992, but we
# haven't verified this yet so for now we'll keep it a single region.
#
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
#
# Buenos Aires (BA), Capital Federal (CF), Santa Cruz (SC),
# Tierra del Fuego, Antartida e Islas del Atlantico Sur (TF)
Zone America/Buenos_Aires -3:53:48 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May # Cordoba Mean Time
-4:00 - ART 1930 Dec
-4:00 Arg AR%sT 1969 Oct 5
-3:00 Arg AR%sT 1999 Oct 3
-4:00 Arg AR%sT 2000 Mar 3
-3:00 - ART
#
# Santa Fe (SF), Entre Rios (ER), Corrientes (CN), Misiones (MN), Chaco (CC),
# Formosa (FM), Salta (SA), Tucuman (TM), Santiago del Estero (SE),
# Cordoba (CB), La Rioja (LR), San Juan (SJ), San Luis (SL), La Pampa (LP),
# Neuquen (NQ), Rio Negro (RN), Chubut (CH)
#
# Shanks also makes the following claims, which we haven't verified:
# - Formosa switched to -3:00 on 1991-01-07.
# - La Rioja and San Juan switched to -4:00 on 1991-03-01
# and then to -3:00 on 1991-05-07.
# - Misiones switched to -3:00 on 1990-12-29.
# - Chaco switched to -3:00 on 1991-01-04.
# - San Luis switched to -4:00 on 1990-03-14, then to -3:00 on 1990-10-15,
# then to -4:00 on 1991-03-01, then to -3:00 on 1991-06-01.
# - Santiago del Estero switched to -4:00 on 1991-04-01,
# then to -3:00 on 1991-04-26.
# If we need to add Zones for these areas, we may need to have a subdirectory
# for Argentina, as e.g. "America/San_Luis" is too ambiguious.
#
Zone America/Cordoba -4:16:48 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May
-4:00 - ART 1930 Dec
-4:00 Arg AR%sT 1969 Oct 5
-3:00 Arg AR%sT 1991 Mar 3
-4:00 - WART 1991 Oct 20
-3:00 Arg AR%sT 1999 Oct 3
-4:00 Arg AR%sT 2000 Mar 3
-3:00 - ART
#
# Jujuy (JY)
Zone America/Jujuy -4:21:12 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May
-4:00 - ART 1930 Dec
-4:00 Arg AR%sT 1969 Oct 5
-3:00 Arg AR%sT 1990 Mar 4
-4:00 - WART 1990 Oct 28
-4:00 1:00 WARST 1991 Mar 17
-4:00 - WART 1991 Oct 6
-3:00 1:00 ARST 1992
-3:00 Arg AR%sT 1999 Oct 3
-4:00 Arg AR%sT 2000 Mar 3
-3:00 - ART
#
# Catamarca (CT)
Zone America/Catamarca -4:23:08 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May
-4:00 - ART 1930 Dec
-4:00 Arg AR%sT 1969 Oct 5
-3:00 Arg AR%sT 1991 Mar 3
-4:00 - WART 1991 Oct 20
-3:00 Arg AR%sT 1999 Oct 3
-4:00 Arg AR%sT 2000 Mar 3
-3:00 - ART
#
# Mendoza (MZ)
Zone America/Mendoza -4:35:16 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May
-4:00 - ART 1930 Dec
-4:00 Arg AR%sT 1969 Oct 5
-3:00 Arg AR%sT 1990 Mar 4
-4:00 - WART 1990 Oct 15
-4:00 1:00 WARST 1991 Mar 1
-4:00 - WART 1991 Oct 15
-4:00 1:00 WARST 1992 Mar 1
-4:00 - WART 1992 Oct 18
-3:00 Arg AR%sT 1999 Oct 3
-4:00 Arg AR%sT 2000 Mar 3
-3:00 - ART
# Aruba
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Aruba -4:40:24 - LMT 1912 Feb 12 # Oranjestad
-4:30 - ANT 1965 # Netherlands Antilles Time
-4:00 - AST
# Bolivia
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/La_Paz -4:32:36 - LMT 1890
-4:32:36 - CMT 1931 Oct 15 # Calamarca MT
-4:32:36 1:00 BOST 1932 Mar 21 # Bolivia ST
-4:00 - BOT # Bolivia Time
# Brazil
# From Paul Eggert <eggert@twinsun.com> (1993-11-18):
# The mayor of Rio recently attempted to change the time zone rules
# just in his city, in order to leave more summer time for the tourist trade.
# The rule change lasted only part of the day;
# the federal government refused to follow the city's rules, and business
# was in a chaos, so the mayor backed down that afternoon.
# From IATA SSIM (1996-02):
# _Only_ the following states in BR1 observe DST: Rio Grande do Sul (RS),
# Santa Catarina (SC), Parana (PR), Sao Paulo (SP), Rio de Janeiro (RJ),
# Espirito Santo (ES), Minas Gerais (MG), Bahia (BA), Goias (GO),
# Distrito Federal (DF), Tocantins (TO), Sergipe [SE] and Alagoas [AL].
# [The last three states are new to this issue of the IATA SSIM.]
# From Gwillim Law (1996-10-07):
# Geography, history (Tocantins was part of Goias until 1989), and other
# sources of time zone information lead me to believe that AL, SE, and TO were
# always in BR1, and so the only change was whether or not they observed DST....
# The earliest issue of the SSIM I have is 2/91. Each issue from then until
# 9/95 says that DST is observed only in the ten states I quoted from 9/95,
# along with Mato Grosso (MT) and Mato Grosso do Sul (MS), which are in BR2
# (UTC-4).... The other two time zones given for Brazil are BR3, which is
# UTC-5, no DST, and applies only in the state of Acre (AC); and BR4, which is
# UTC-2, and applies to Fernando de Noronha (formerly FN, but I believe it's
# become part of the state of Pernambuco). The boundary between BR1 and BR2
# has never been clearly stated. They've simply been called East and West.
# However, some conclusions can be drawn from another IATA manual: the Airline
# Coding Directory, which lists close to 400 airports in Brazil. For each
# airport it gives a time zone which is coded to the SSIM. From that
# information, I'm led to conclude that the states of Amapa (AP), Ceara (CE),
# Maranhao (MA), Paraiba (PR), Pernambuco (PE), Piaui (PI), and Rio Grande do
# Norte (RN), and the eastern part of Para (PA) are all in BR1 without DST.
# From Marcos Tadeu (1998-09-27):
# <a href="http://pcdsh01.on.br/verao1.html">
# Brazilian official page
# </a>
# From Jesper Norgaard (2000-11-03):
# [For an official list of which regions in Brazil use which time zones, see:]
# http://pcdsh01.on.br/Fusbr.htm
# http://pcdsh01.on.br/Fusbrhv.htm
# From Celso Doria via David Madeo (2002-10-09):
# The reason for the delay this year has to do with elections in Brazil.
#
# Unlike in the United States, elections in Brazil are 100% computerized and
# the results are known almost immediately. Yesterday, it was the first
# round of the elections when 115 million Brazilians voted for President,
# Governor, Senators, Federal Deputies, and State Deputies. Nobody is
# counting (or re-counting) votes anymore and we know there will be a second
# round for the Presidency and also for some Governors. The 2nd round will
# take place on October 27th.
#
# The reason why the DST will only begin November 3rd is that the thousands
# of electoral machines used cannot have their time changed, and since the
# Constitution says the elections must begin at 8:00 AM and end at 5:00 PM,
# the Government decided to postpone DST, instead of changing the Constitution
# (maybe, for the next elections, it will be possible to change the clock)...
# From Paul Eggert (2002-10-10):
# The official decrees referenced below are mostly taken from
# <a href="http://pcdsh01.on.br/DecHV.html">
# Decretos sobre o Horario de Verao no Brasil
# </a> (2001-09-20, in Portuguese).
# The official site for all decrees, including those not related to time, is
# <a href="http://www.presidencia.gov.br/CCIVIL/decreto/principal_ano.htm">
# Presidencia da Republica, Subchefia para Assuntos Juridicos, Decretos
# </a> (in Portuguese).
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
# Decree <a href="http://pcdsh01.on.br/HV20466.htm">20,466</a> (1931-10-01)
# Decree <a href="http://pcdsh01.on.br/HV21896.htm">21,896</a> (1932-01-10)
Rule Brazil 1931 only - Oct 3 11:00 1:00 S
Rule Brazil 1932 1933 - Apr 1 0:00 0 -
Rule Brazil 1932 only - Oct 3 0:00 1:00 S
# Decree <a href="http://pcdsh01.on.br/HV23195.htm">23,195</a> (1933-10-10)
# revoked DST.
# Decree <a href="http://pcdsh01.on.br/HV27496.htm">27,496</a> (1949-11-24)
# Decree <a href="http://pcdsh01.on.br/HV27998.htm">27,998</a> (1950-04-13)
Rule Brazil 1949 1952 - Dec 1 0:00 1:00 S
Rule Brazil 1950 only - Apr 16 1:00 0 -
Rule Brazil 1951 1952 - Apr 1 0:00 0 -
# Decree <a href="http://pcdsh01.on.br/HV32308.htm">32,308</a> (1953-02-24)
Rule Brazil 1953 only - Mar 1 0:00 0 -
# Decree <a href="http://pcdsh01.on.br/HV34724.htm">34,724</a> (1953-11-30)
# revoked DST.
# Decree <a href="http://pcdsh01.on.br/HV52700.htm">52,700</a> (1963-10-18)
# established DST from 1963-10-23 00:00 to 1964-02-29 00:00
# in SP, RJ, GB, MG, ES, due to the prolongation of the drought.
# Decree <a href="http://pcdsh01.on.br/HV53071.htm">53,071</a> (1963-12-03)
# extended the above decree to all of the national territory on 12-09.
Rule Brazil 1963 only - Dec 9 0:00 1:00 S
# Decree <a href="http://pcdsh01.on.br/HV53604.htm">53,604</a> (1964-02-25)
# extended summer time by one day to 1964-03-01 00:00 (start of school).
Rule Brazil 1964 only - Mar 1 0:00 0 -
# Decree <a href="http://pcdsh01.on.br/HV55639.htm">55,639</a> (1965-01-27)
Rule Brazil 1965 only - Jan 31 0:00 1:00 S
Rule Brazil 1965 only - Mar 31 0:00 0 -
# Decree <a href="http://pcdsh01.on.br/HV57303.htm">57,303</a> (1965-11-22)
Rule Brazil 1965 only - Dec 1 0:00 1:00 S
# Decree <a href="http://pcdsh01.on.br/HV57843.htm">57,843</a> (1966-02-18)
Rule Brazil 1966 1968 - Mar 1 0:00 0 -
Rule Brazil 1966 1967 - Nov 1 0:00 1:00 S
# Decree <a href="http://pcdsh01.on.br/HV63429.htm">63,429</a> (1968-10-15)
# revoked DST.
# Decree <a href="http://pcdsh01.on.br/HV91698.htm">91,698</a> (1985-09-27)
Rule Brazil 1985 only - Nov 2 0:00 1:00 S
# Decree 92,310 (1986-01-21)
# Decree 92,463 (1986-03-13)
Rule Brazil 1986 only - Mar 15 0:00 0 -
# Decree 93,316 (1986-10-01)
Rule Brazil 1986 only - Oct 25 0:00 1:00 S
Rule Brazil 1987 only - Feb 14 0:00 0 -
# Decree <a href="http://pcdsh01.on.br/HV94922.htm">94,922</a> (1987-09-22)
Rule Brazil 1987 only - Oct 25 0:00 1:00 S
Rule Brazil 1988 only - Feb 7 0:00 0 -
# Decree <a href="http://pcdsh01.on.br/HV96676.htm">96,676</a> (1988-09-12)
# except for the states of AC, AM, PA, RR, RO, and AP (then a territory)
Rule Brazil 1988 only - Oct 16 0:00 1:00 S
Rule Brazil 1989 only - Jan 29 0:00 0 -
# Decree <a href="http://pcdsh01.on.br/HV98077.htm">98,077</a> (1989-08-21)
# with the same exceptions
Rule Brazil 1989 only - Oct 15 0:00 1:00 S
Rule Brazil 1990 only - Feb 11 0:00 0 -
# Decree <a href="http://pcdsh01.on.br/HV99530.htm">99,530</a> (1990-09-17)
# adopted by RS, SC, PR, SP, RJ, ES, MG, GO, MS, DF.
# Decree 99,629 (1990-10-19) adds BA, MT.
Rule Brazil 1990 only - Oct 21 0:00 1:00 S
Rule Brazil 1991 only - Feb 17 0:00 0 -
# <a href="http://pcdsh01.on.br/HV1991.htm">Unnumbered decree</a> (1991-09-25)
# adopted by RS, SC, PR, SP, RJ, ES, MG, BA, GO, MT, MS, DF.
Rule Brazil 1991 only - Oct 20 0:00 1:00 S
Rule Brazil 1992 only - Feb 9 0:00 0 -
# <a href="http://pcdsh01.on.br/HV1992.htm">Unnumbered decree</a> (1992-10-16)
# adopted by same states.
Rule Brazil 1992 only - Oct 25 0:00 1:00 S
Rule Brazil 1993 only - Jan 31 0:00 0 -
# Decree <a href="http://pcdsh01.on.br/HV942.htm">942</a> (1993-09-28)
# adopted by same states, plus AM.
# Decree <a href="http://pcdsh01.on.br/HV1252.htm">1,252</a> (1994-09-22)
# adopted by same states, minus AM.
# Decree <a href="http://pcdsh01.on.br/HV1636.htm">1,636</a> (1995-09-14)
# adopted by same states, plus TO.
# Decree <a href="http://pcdsh01.on.br/HV1674.htm">1,674</a> (1995-10-13)
# adds AL, SE.
Rule Brazil 1993 1995 - Oct Sun>=11 0:00 1:00 S
Rule Brazil 1994 1995 - Feb Sun>=15 0:00 0 -
Rule Brazil 1996 only - Feb 11 0:00 0 -
# Decree <a href="http://pcdsh01.on.br/HV2000.htm">2,000</a> (1996-09-04)
# adopted by same states, minus AL, SE.
Rule Brazil 1996 only - Oct 6 0:00 1:00 S
Rule Brazil 1997 only - Feb 16 0:00 0 -
# From Daniel C. Sobral <dcs@gns.com.br> (1998-02-12):
# In 1997, the DS began on October 6. The stated reason was that
# because international television networks ignored Brazil's policy on DS,
# they bought the wrong times on satellite for coverage of Pope's visit.
# This year, the ending date of DS was postponed to March 1
# to help dealing with the shortages of electric power.
#
# From Paul Eggert (1998-02-25):
# <a href="http://churchnet.ucsm.ac.uk/news/files2/news165.htm">
# Brazil Prepares for Papal Visit
# </a>,
# Church Net UK (1997-10-02).
#
# Decree 2,317 (1997-09-04), adopted by same states.
Rule Brazil 1997 only - Oct 6 0:00 1:00 S
# Decree <a href="http://pcdsh01.on.br/figuras/HV2495.JPG">2,495</a>
# (1998-02-10)
Rule Brazil 1998 only - Mar 1 0:00 0 -
# Decree <a href="http://pcdsh01.on.br/figuras/Hv98.jpg">2,780</a> (1998-09-11)
# adopted by the same states as before.
Rule Brazil 1998 only - Oct 11 0:00 1:00 S
Rule Brazil 1999 only - Feb 21 0:00 0 -
# Decree <a href="http://pcdsh01.on.br/figuras/HV3150.gif">3,150</a>
# (1999-08-23) adopted by same states.
# Decree <a href="http://pcdsh01.on.br/DecHV99.gif">3,188</a> (1999-09-30)
# adds SE, AL, PB, PE, RN, CE, PI, MA and RR.
Rule Brazil 1999 only - Oct 3 0:00 1:00 S
Rule Brazil 2000 only - Feb 27 0:00 0 -
# Decree <a href="http://pcdsh01.on.br/DEC3592.htm">3,592</a> (2000-09-06)
# adopted by the same states as before.
# Decree <a href="http://pcdsh01.on.br/Dec3630.jpg">3,630</a> (2000-10-13)
# repeals DST in PE and RR, effective 2000-10-15 00:00.
# Decree <a href="http://pcdsh01.on.br/Dec3632.jpg">3,632</a> (2000-10-17)
# repeals DST in SE, AL, PB, RN, CE, PI and MA, effective 2000-10-22 00:00.
# Decree <a href="http://pcdsh01.on.br/figuras/HV3916.gif">3,916</a>
# (2001-09-13) reestablishes DST in AL, CE, MA, PB, PE, PI, RN, SE.
Rule Brazil 2000 2001 - Oct Sun>=8 0:00 1:00 S
Rule Brazil 2001 max - Feb Sun>=15 0:00 0 -
# Decree 4,399 (2002-10-01) repeals DST in AL, CE, MA, PB, PE, PI, RN, SE.
# <a href="http://www.presidencia.gov.br/CCIVIL/decreto/2002/D4399.htm"></a>
Rule Brazil 2002 only - Nov 3 0:00 1:00 S
# Decree 4,844 (2003-09-24; corrected 2003-09-26) repeals DST in BA, MT, TO.
# <a href="http://www.presidencia.gov.br/CCIVIL/decreto/2003/D4844.htm"></a>
Rule Brazil 2003 max - Oct Sun>=15 0:00 1:00 S
# The latest ruleset listed above says that the following states observe DST:
# DF, ES, GO, MG, MS, PR, RJ, RS, SC, SP.
#
# For dates after mid-2004, the above rules with TO="max" are guesses
# and are quite possibly wrong, but are more likely than no DST at all.
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
#
# Atlantic islands: Fernando de Noronha, Trindade, Martin Vaz,
# Atol das Rocas, and Penedos de Sao Pedro e Sao Paulo
Zone America/Noronha -2:09:40 - LMT 1914
-2:00 Brazil FN%sT 1990 Sep 17
-2:00 - FNT
#
# Amapa (AP), east Para (PA)
# East Para includes Belem, Maraba, Serra Norte, and Sao Felix do Xingu.
# The division between east and west Para is the river Xingu.
# In the north a very small part from the river Javary (now Jari I guess,
# the border with Amapa) to the Amazon, then to the Xingu.
Zone America/Belem -3:13:56 - LMT 1914
-3:00 Brazil BR%sT 1988 Sep 12
-3:00 - BRT
#
# Maranhao (MA), Piaui (PI), Ceara (CE), Rio Grande do Norte (RN),
# Paraiba (PB)
Zone America/Fortaleza -2:34:00 - LMT 1914
-3:00 Brazil BR%sT 1990 Sep 17
-3:00 - BRT 1999 Sep 30
-3:00 Brazil BR%sT 2000 Oct 22
-3:00 - BRT 2001 Sep 13
-3:00 Brazil BR%sT 2002 Oct 1
-3:00 - BRT
#
# Pernambuco (PE) (except Atlantic islands)
Zone America/Recife -2:19:36 - LMT 1914
-3:00 Brazil BR%sT 1990 Sep 17
-3:00 - BRT 1999 Sep 30
-3:00 Brazil BR%sT 2000 Oct 15
-3:00 - BRT 2001 Sep 13
-3:00 Brazil BR%sT 2002 Oct 1
-3:00 - BRT
#
# Tocantins (TO)
Zone America/Araguaina -3:12:48 - LMT 1914
-3:00 Brazil BR%sT 1990 Sep 17
-3:00 - BRT 1995 Sep 14
-3:00 Brazil BR%sT 2003 Sep 24
-3:00 - BRT
#
# Alagoas (AL), Sergipe (SE)
Zone America/Maceio -2:22:52 - LMT 1914
-3:00 Brazil BR%sT 1990 Sep 17
-3:00 - BRT 1995 Oct 13
-3:00 Brazil BR%sT 1996 Sep 4
-3:00 - BRT 1999 Sep 30
-3:00 Brazil BR%sT 2000 Oct 22
-3:00 - BRT 2001 Sep 13
-3:00 Brazil BR%sT 2002 Oct 1
-3:00 - BRT
#
# Bahia (BA)
# There are too many Salvadors elsewhere, so use America/Bahia instead
# of America/Salvador.
Zone America/Bahia -2:34:04 - LMT 1914
-3:00 Brazil BR%sT 2003 Sep 24
-3:00 - BRT
#
# Goias (GO), Distrito Federal (DF), Minas Gerais (MG),
# Espirito Santo (ES), Rio de Janeiro (RJ), Sao Paulo (SP), Parana (PR),
# Santa Catarina (SC), Rio Grande do Sul (RS)
Zone America/Sao_Paulo -3:06:28 - LMT 1914
-3:00 Brazil BR%sT 1963 Oct 23 00:00
-3:00 1:00 BRST 1964
-3:00 Brazil BR%sT
#
# Mato Grosso do Sul (MS)
Zone America/Campo_Grande -3:38:28 - LMT 1914
-4:00 Brazil AM%sT
#
# Mato Grosso (MT)
Zone America/Cuiaba -3:44:20 - LMT 1914
-4:00 Brazil AM%sT 2003 Sep 24
-4:00 - AMT
#
# west Para (PA), Rondonia (RO)
# West Para includes Altamira, Oribidos, Prainha, Oriximina, and Santarem.
Zone America/Porto_Velho -4:15:36 - LMT 1914
-4:00 Brazil AM%sT 1988 Sep 12
-4:00 - AMT
#
# Roraima (RR)
Zone America/Boa_Vista -4:02:40 - LMT 1914
-4:00 Brazil AM%sT 1988 Sep 12
-4:00 - AMT 1999 Sep 30
-4:00 Brazil AM%sT 2000 Oct 15
-4:00 - AMT
#
# east Amazonas (AM): Boca do Acre, Jutai, Manaus, Floriano Peixoto
# The great circle line from Tabatinga to Porto Acre divides
# east from west Amazonas.
Zone America/Manaus -4:00:04 - LMT 1914
-4:00 Brazil AM%sT 1988 Sep 12
-4:00 - AMT 1993 Sep 28
-4:00 Brazil AM%sT 1994 Sep 22
-4:00 - AMT
#
# west Amazonas (AM): Atalaia do Norte, Boca do Maoco, Benjamin Constant,
# Eirunepe, Envira, Ipixuna
Zone America/Eirunepe -4:39:28 - LMT 1914
-5:00 Brazil AC%sT 1988 Sep 12
-5:00 - ACT 1993 Sep 28
-5:00 Brazil AC%sT 1994 Sep 22
-5:00 - ACT
#
# Acre (AC)
Zone America/Rio_Branco -4:31:12 - LMT 1914
-5:00 Brazil AC%sT 1988 Sep 12
-5:00 - ACT
# Chile
# From Eduardo Krell (1995-10-19):
# The law says to switch to DST at midnight [24:00] on the second SATURDAY
# of October.... The law is the same for March and October.
# (1998-09-29):
# Because of the drought this year, the government decided to go into
# DST earlier (saturday 9/26 at 24:00). This is a one-time change only ...
# (unless there's another dry season next year, I guess).
# From Julio I. Pacheco Troncoso (1999-03-18):
# Because of the same drought, the government decided to end DST later,
# on April 3, (one-time change).
# From Gwillim Law (2001-05-04):
# I came across another article in "La Tercera" about Chilean DST.
# <http://www.tercera.cl/diario/2000/10/13/t-extras.html>
# It clearly confirms my earlier suggestion, that DST begins at 22:00
# on Easter Island.... But it also seems to be saying that the
# observance of DST in Chile began in 1966, rather than 1969 as
# ... [Shanks] has it....
#
# My translation:
#
# "The Chilean Army has announced that summer time will begin tomorrow,
# Saturday, October 14 in continental Chile, insular Chile, and
# Antarctica, as provided by Supreme Decree 25 of January 11, 1966.
# By the preceding, official time in continental Chile and Chilean
# Antarctic, and official time in Western Insular Chile, which applies
# to Easter Island and Sala y Gomez Island, will be set forward at
# midnight and at 22:00, respectively, by 20 minutes."
# From Paul Eggert (2001-05-04):
# Go with this article in preference to Shanks's 1969 date for modern DST.
# Assume this rule has been used since DST was introduced in the islands.
# From Paul Eggert (2002-10-24):
# <http://www.shoa.cl/shoa/faqhoraoficial.htm> gives many details that
# disagree with the following table, but we haven't had time to compare them.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Chile 1918 only - Sep 1 0:00 1:00 S
Rule Chile 1919 only - Jul 2 0:00 0 -
Rule Chile 1927 1931 - Sep 1 0:00 1:00 S
Rule Chile 1928 1932 - Apr 1 0:00 0 -
Rule Chile 1966 1997 - Oct Sun>=9 4:00u 1:00 S
Rule Chile 1967 1998 - Mar Sun>=9 3:00u 0 -
Rule Chile 1998 only - Sep 27 4:00u 1:00 S
Rule Chile 1999 only - Apr 4 3:00u 0 -
Rule Chile 1999 max - Oct Sun>=9 4:00u 1:00 S
Rule Chile 2000 max - Mar Sun>=9 3:00u 0 -
# IATA SSIM anomalies: (1990-09) says 1990-09-16; (1992-02) says 1992-03-14;
# (1996-09) says 1998-03-08. Ignore these.
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Santiago -4:42:40 - LMT 1890
-4:42:40 - SMT 1910 # Santiago Mean Time
-5:00 Chile CL%sT 1932 Sep # Chile Time
-4:00 Chile CL%sT
Zone Pacific/Easter -7:17:28 - LMT 1890 # Mataveri
-7:17:28 - MMT 1932 Sep # Mataveri Mean Time
-7:00 Chile EAS%sT 1982 Mar 14 # Easter I Time
-6:00 Chile EAS%sT
#
# Sala y Gomez Island is like Pacific/Easter.
# Other Chilean locations, including Juan Fernandez Is, San Ambrosio,
# San Felix, and Antarctic bases, are like America/Santiago.
# Colombia
# Shanks specifies 24:00 for 1992 transition times; go with IATA,
# as it seems implausible to change clocks at midnight New Year's Eve.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule CO 1992 only - May 2 0:00 1:00 S
Rule CO 1992 only - Dec 31 0:00 0 -
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Bogota -4:56:20 - LMT 1884 Mar 13
-4:56:20 - BMT 1914 Nov 23 # Bogota Mean Time
-5:00 CO CO%sT # Colombia Time
# Malpelo, Providencia, San Andres
# no information; probably like America/Bogota
# Curacao
# Shanks says that Bottom and Oranjestad have been at -4:00 since
# standard time was introduced on 1912-03-02; and that Kralendijk and Rincon
# used Kralendijk Mean Time (-4:33:08) from 1912-02-02 to 1965-01-01.
# This all predates our 1970 cutoff, though.
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Curacao -4:35:44 - LMT 1912 Feb 12 # Willemstad
-4:30 - ANT 1965 # Netherlands Antilles Time
-4:00 - AST
# Ecuador
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Guayaquil -5:19:20 - LMT 1890
-5:14:00 - QMT 1931 # Quito Mean Time
-5:00 - ECT # Ecuador Time
Zone Pacific/Galapagos -5:58:24 - LMT 1931 # Puerto Baquerizo Moreno
-5:00 - ECT 1986
-6:00 - GALT # Galapagos Time
# Falklands
# From Paul Eggert (2001-03-05):
# Between 1990 and 2000 inclusive, Shanks and the IATA agree except
# the IATA gives 1996-09-08. Go with Shanks.
# From Falkland Islands Government Office, London (2001-01-22)
# via Jesper Norgaard:
# ... the clocks revert back to Local Mean Time at 2 am on Sunday 15
# April 2001 and advance one hour to summer time at 2 am on Sunday 2
# September. It is anticipated that the clocks will revert back at 2
# am on Sunday 21 April 2002 and advance to summer time at 2 am on
# Sunday 1 September.
# From Rives McDow (2001-02-13):
#
# I have communicated several times with people there, and the last
# time I had communications that was helpful was in 1998. Here is
# what was said then:
#
# "The general rule was that Stanley used daylight saving and the Camp
# did not. However for various reasons many people in the Camp have
# started to use daylight saving (known locally as 'Stanley Time')
# There is no rule as to who uses daylight saving - it is a matter of
# personal choice and so it is impossible to draw a map showing who
# uses it and who does not. Any list would be out of date as soon as
# it was produced. This year daylight saving ended on April 18/19th
# and started again on September 12/13th. I do not know what the rule
# is, but can find out if you like. We do not change at the same time
# as UK or Chile."
#
# I did have in my notes that the rule was "Second Saturday in Sep at
# 0:00 until third Saturday in Apr at 0:00". I think that this does
# not agree in some cases with Shanks; is this true?
#
# Also, there is no mention in the list that some areas in the
# Falklands do not use DST. I have found in my communications there
# that these areas are on the western half of East Falkland and all of
# West Falkland. Stanley is the only place that consistently observes
# DST. Again, as in other places in the world, the farmers don't like
# it. West Falkland is almost entirely sheep farmers.
#
# I know one lady there that keeps a list of which farm keeps DST and
# which doesn't each year. She runs a shop in Stanley, and says that
# the list changes each year. She uses it to communicate to her
# customers, catching them when they are home for lunch or dinner.
# From Paul Eggert (2001-03-05):
# For now, we'll just record the time in Stanley, since we have no
# better info.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Falk 1937 1938 - Sep lastSun 0:00 1:00 S
Rule Falk 1938 1942 - Mar Sun>=19 0:00 0 -
Rule Falk 1939 only - Oct 1 0:00 1:00 S
Rule Falk 1940 1942 - Sep lastSun 0:00 1:00 S
Rule Falk 1943 only - Jan 1 0:00 0 -
Rule Falk 1983 only - Sep lastSun 0:00 1:00 S
Rule Falk 1984 1985 - Apr lastSun 0:00 0 -
Rule Falk 1984 only - Sep 16 0:00 1:00 S
Rule Falk 1985 2000 - Sep Sun>=9 0:00 1:00 S
Rule Falk 1986 2000 - Apr Sun>=16 0:00 0 -
Rule Falk 2001 max - Apr Sun>=15 2:00 0 -
Rule Falk 2001 max - Sep Sun>=1 2:00 1:00 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone Atlantic/Stanley -3:51:24 - LMT 1890
-3:51:24 - SMT 1912 Mar 12 # Stanley Mean Time
-4:00 Falk FK%sT 1983 May # Falkland Is Time
-3:00 Falk FK%sT 1985 Sep 15
-4:00 Falk FK%sT
# French Guiana
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Cayenne -3:29:20 - LMT 1911 Jul
-4:00 - GFT 1967 Oct # French Guiana Time
-3:00 - GFT
# Guyana
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Guyana -3:52:40 - LMT 1915 Mar # Georgetown
-3:45 - GBGT 1966 May 26 # Br Guiana Time
-3:45 - GYT 1975 Jul 31 # Guyana Time
-3:00 - GYT 1991
# IATA SSIM (1996-06) says -4:00. Assume a 1991 switch.
-4:00 - GYT
# Paraguay
# From Paul Eggert (1999-10-29):
# Shanks (1999) says that spring transitions are from 01:00 -> 02:00,
# and autumn transitions are from 00:00 -> 23:00. Go with earlier
# editions of Shanks, and with the IATA, who say transitions occur at 00:00.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Para 1975 1988 - Oct 1 0:00 1:00 S
Rule Para 1975 1978 - Mar 1 0:00 0 -
Rule Para 1979 1991 - Apr 1 0:00 0 -
Rule Para 1989 only - Oct 22 0:00 1:00 S
Rule Para 1990 only - Oct 1 0:00 1:00 S
Rule Para 1991 only - Oct 6 0:00 1:00 S
Rule Para 1992 only - Mar 1 0:00 0 -
Rule Para 1992 only - Oct 5 0:00 1:00 S
Rule Para 1993 only - Mar 31 0:00 0 -
Rule Para 1993 1995 - Oct 1 0:00 1:00 S
Rule Para 1994 1995 - Feb lastSun 0:00 0 -
Rule Para 1996 only - Mar 1 0:00 0 -
# IATA SSIM (2000-02) says 1999-10-10; ignore this for now.
# From Steffen Thorsen (2000-10-02):
# I have three independent reports that Paraguay changed to DST this Sunday
# (10-01).
#
# Translated by Gwillim Law (2001-02-27) from
# <a href="http://www.diarionoticias.com.py/011000/nacional/naciona1.htm">
# Noticias, a daily paper in Asuncion, Paraguay (2000-10-01)
# </a>:
# Starting at 0:00 today, the clock will be set forward 60 minutes, in
# fulfillment of Decree No. 7,273 of the Executive Power.... The time change
# system has been operating for several years. Formerly there was a separate
# decree each year; the new law has the same effect, but permanently. Every
# year, the time will change on the first Sunday of October; likewise, the
# clock will be set back on the first Sunday of March.
#
# From Jesper Norgaard (2001-03-06) [an official URL saying similar things]:
# http://gateway.abc.com.py:8000/pub/pag04.mbr/artic?FHA=2001-03-03-02.24.52.900592
#
Rule Para 1996 2001 - Oct Sun>=1 0:00 1:00 S
# IATA SSIM (1997-09) says Mar 1; go with Shanks.
Rule Para 1997 only - Feb lastSun 0:00 0 -
# Shanks says 1999-02-28; IATA SSIM (1999-02) says 1999-02-27, but
# (1999-09) reports no date; go with above sources and Gerd Knops (2001-02-27).
Rule Para 1998 2001 - Mar Sun>=1 0:00 0 -
# From Rives McDow (2002-02-28):
# A decree was issued in Paraguay (no. 16350) on 2002-02-26 that changed the
# dst method to be from the first Sunday in September to the first Sunday in
# April.
Rule Para 2002 max - Apr Sun>=1 0:00 0 -
Rule Para 2002 max - Sep Sun>=1 0:00 1:00 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Asuncion -3:50:40 - LMT 1890
-3:50:40 - AMT 1931 Oct 10 # Asuncion Mean Time
-4:00 - PYT 1972 Oct # Paraguay Time
-3:00 - PYT 1974 Apr
-4:00 Para PY%sT
# Peru
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Peru 1938 only - Jan 1 0:00 1:00 S
Rule Peru 1938 only - Apr 1 0:00 0 -
Rule Peru 1938 1939 - Sep lastSun 0:00 1:00 S
Rule Peru 1939 1940 - Mar Sun>=24 0:00 0 -
Rule Peru 1987 only - Jan 1 0:00 1:00 S
Rule Peru 1987 only - Apr 1 0:00 0 -
Rule Peru 1990 only - Jan 1 0:00 1:00 S
Rule Peru 1990 only - Apr 1 0:00 0 -
# IATA is ambiguous for 1993/1995; go with Shanks.
Rule Peru 1994 only - Jan 1 0:00 1:00 S
Rule Peru 1994 only - Apr 1 0:00 0 -
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Lima -5:08:12 - LMT 1890
-5:08:36 - LMT 1908 Jul 28 # Lima Mean Time?
-5:00 Peru PE%sT # Peru Time
# South Georgia
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone Atlantic/South_Georgia -2:26:08 - LMT 1890 # Grytviken
-2:00 - GST # South Georgia Time
# South Sandwich Is
# uninhabited; scientific personnel have wintered
# Suriname
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Paramaribo -3:40:40 - LMT 1911
-3:40:52 - PMT 1935 # Paramaribo Mean Time
-3:40:36 - PMT 1945 Oct # The capital moved?
-3:30 - NEGT 1975 Nov 20 # Dutch Guiana Time
-3:30 - SRT 1984 Oct # Suriname Time
-3:00 - SRT
# Trinidad and Tobago
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Port_of_Spain -4:06:04 - LMT 1912 Mar 2
-4:00 - AST
# Uruguay
# From Paul Eggert <eggert@twinsun.com> (1993-11-18):
# Uruguay wins the prize for the strangest peacetime manipulation of the rules.
# From Shanks:
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
# Whitman gives 1923 Oct 1; go with Shanks.
Rule Uruguay 1923 only - Oct 2 0:00 0:30 HS
Rule Uruguay 1924 1926 - Apr 1 0:00 0 -
Rule Uruguay 1924 1925 - Oct 1 0:00 0:30 HS
Rule Uruguay 1933 1935 - Oct lastSun 0:00 0:30 HS
# Shanks gives 1935 Apr 1 0:00 and 1936 Mar 30 0:00; go with Whitman.
Rule Uruguay 1934 1936 - Mar Sat>=25 23:30s 0 -
Rule Uruguay 1936 only - Nov 1 0:00 0:30 HS
Rule Uruguay 1937 1941 - Mar lastSun 0:00 0 -
# Whitman gives 1937 Oct 3; go with Shanks.
Rule Uruguay 1937 1940 - Oct lastSun 0:00 0:30 HS
# Whitman gives 1941 Oct 24 - 1942 Mar 27, 1942 Dec 14 - 1943 Apr 13,
# and 1943 Apr 13 ``to present time''; go with Shanks.
Rule Uruguay 1941 only - Aug 1 0:00 0 -
Rule Uruguay 1942 only - Jan 1 0:00 0:30 HS
Rule Uruguay 1942 only - Dec 14 0:00 1:00 S
Rule Uruguay 1943 only - Mar 14 0:00 0 -
Rule Uruguay 1959 only - May 24 0:00 1:00 S
Rule Uruguay 1959 only - Nov 15 0:00 0 -
Rule Uruguay 1960 only - Jan 17 0:00 1:00 S
Rule Uruguay 1960 only - Mar 6 0:00 0 -
Rule Uruguay 1965 1967 - Apr Sun>=1 0:00 1:00 S
Rule Uruguay 1965 only - Sep 26 0:00 0 -
Rule Uruguay 1966 1967 - Oct 31 0:00 0 -
Rule Uruguay 1968 1970 - May 27 0:00 0:30 HS
Rule Uruguay 1968 1970 - Dec 2 0:00 0 -
Rule Uruguay 1972 only - Apr 24 0:00 1:00 S
Rule Uruguay 1972 only - Aug 15 0:00 0 -
Rule Uruguay 1974 only - Mar 10 0:00 0:30 HS
Rule Uruguay 1974 only - Dec 22 0:00 1:00 S
Rule Uruguay 1976 only - Oct 1 0:00 0 -
Rule Uruguay 1977 only - Dec 4 0:00 1:00 S
Rule Uruguay 1978 only - Apr 1 0:00 0 -
Rule Uruguay 1979 only - Oct 1 0:00 1:00 S
Rule Uruguay 1980 only - May 1 0:00 0 -
Rule Uruguay 1987 only - Dec 14 0:00 1:00 S
Rule Uruguay 1988 only - Mar 14 0:00 0 -
Rule Uruguay 1988 only - Dec 11 0:00 1:00 S
Rule Uruguay 1989 only - Mar 12 0:00 0 -
Rule Uruguay 1989 only - Oct 29 0:00 1:00 S
# Shanks says no DST was observed in 1990/1 and 1991/2,
# and that 1992/3's DST was from 10-25 to 03-01. Go with IATA.
Rule Uruguay 1990 1992 - Mar Sun>=1 0:00 0 -
Rule Uruguay 1990 1991 - Oct Sun>=21 0:00 1:00 S
Rule Uruguay 1992 only - Oct 18 0:00 1:00 S
Rule Uruguay 1993 only - Feb 28 0:00 0 -
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Montevideo -3:44:44 - LMT 1898 Jun 28
-3:44:44 - MMT 1920 May 1 # Montevideo MT
-3:30 Uruguay UY%sT 1942 Dec 14 # Uruguay Time
-3:00 Uruguay UY%sT
# Venezuela
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Caracas -4:27:44 - LMT 1890
-4:27:40 - CMT 1912 Feb 12 # Caracas Mean Time?
-4:30 - VET 1965 # Venezuela Time
-4:00 - VET
|