I get it now... thanx for the info... I actually don't know what version of the southamerica files the machines were using, 'cause the default installation doesn't include the zonefiles sources, just the compiled ones. It might be that the RH7 distrib wasn't wrong, but as that was a non- production machine, someone might have been fiddling with it before I started to work. On the RH6.2 machines, when I started, I compiled the new zones for southamerica (2001a, anyway, southamerica didn't change), but I forgot to link to /etc/localtime... before realizing that, I started looking at the source itself and, not understanding it, I erased the year 2000 lines... after nothing changing I realized the link to /etc/localtime was a hard one so the version in /etc/localtime was the old one... by this time I had already edited it and after linking again, it worked. So, most probably, RH6.2 comes with an old version of southamerica that starts using DST in 2000, but the new versions are OK. I realize that the lines I erased have, in fact, no actual change in "wall" clock time... it only says wether it's summer or not :-). I find it easier to not have "useless" rules in the file originated in decrees that were derogated before they were actually effective, so I edited the zoneinfo file for southamerica to reflect this. I don't know what the policy of the WG is regarding this kind of changes, but I attach the modified file and include a "diff" output down here, FWIW. I really thank Paul his advice. ==================================================================== # diff southamerica.2001b southamerica.ar-clean 1c1 < # @(#)southamerica 7.40 ---

# @(#)southamerica 7.41 111,127d110 < # 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. < # 136,137c119 < -3:00 Arg AR%sT 1999 Oct 3 0:00 < -4:00 Arg AR%sT 2000 Mar 3 0:00

-3:00 Arg AR%sT 1993 Oct 3 0:00

147,148d128 < -3:00 - ART 1999 Oct 3 0:00 < -4:00 Arg AR%sT 2000 Mar 3 0:00 158,159d137 < -3:00 - ART 1999 Oct 3 0:00 < -4:00 Arg AR%sT 2000 Mar 3 0:00 171,172d148 < -3:00 - ART 1999 Oct 3 0:00 < -4:00 Arg AR%sT 2000 Mar 3 0:00 183,184d158 < -3:00 - ART 1999 Oct 3 0:00 < -4:00 Arg AR%sT 2000 Mar 3 0:00 196,197d169 < -3:00 - ART 1999 Oct 3 0:00 < -4:00 Arg AR%sT 2000 Mar 3 0:00 ==================================================================== El 16 Apr 2001, a las 17:51, Paul Eggert escribió:

...

From: "Mariano Absatz" <baby@baby.com.ar> Date: Mon, 16 Apr 2001 19:30:47 -0300

I administer a bunch of Solaris and Linux (RedHat 6.x/7.x) machines and a month or so ago, all of the Linuxes went one hour early...

That's odd. I just checked my Red Hat 7.x box, and the shell command:

/usr/sbin/zdump -v America/Buenos_Aires | egrep '199[3-9]|200[0-9]'

outputs:

America/Buenos_Aires Sun Mar 7 01:59:59 1993 UTC = Sat Mar 6 23:59:59 1993 ARST isdst=1 gmtoff=-7200 America/Buenos_Aires Sun Mar 7 02:00:00 1993 UTC = Sat Mar 6 23:00:00 1993 ART isdst=0 gmtoff=-10800 America/Buenos_Aires Sun Oct 3 02:59:59 1999 UTC = Sat Oct 2 23:59:59 1999 ART isdst=0 gmtoff=-10800 America/Buenos_Aires Sun Oct 3 03:00:00 1999 UTC = Sun Oct 3 00:00:00 1999 ARST isdst=1 gmtoff=-10800 America/Buenos_Aires Fri Mar 3 02:59:59 2000 UTC = Thu Mar 2 23:59:59 2000 ARST isdst=1 gmtoff=-10800 America/Buenos_Aires Fri Mar 3 03:00:00 2000 UTC = Fri Mar 3 00:00:00 2000 ART isdst=0 gmtoff=-10800

which means that the wall clocks haven't been adjusted since 1993-03-06, though the DST indicator and the time zone abbreviation did change in summer 1999/2000 due to a canceled experiment.

Perhaps your Red Hat boxes are using an older version of the tz tables. For example, if they are using revision 7.34 of the southamerica file, that would explain the matter. If so, upgrading to the latest version of the tz tables should fix the problem.

...

I just saw that there is another release (2001b), but the bug is still there...

How did you test 2001b? I just tried it, and it gave the same results as above, which matches what you report: Argentina is 3 hours behind UTC and does not observe DST.

...

Is there a somehow concise explanation of the format of the zoneinfo files, other than the comments in the file itself?

Yes; the zic man page. Try the shell command "man zic".

-- Mariano Absatz baby@baby.com.ar # @(#)southamerica 7.41 # 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 <Gwil_Law@bridge-point.com> 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 1 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 1974 1976 - Oct Sun>=1 0:00 1:00 S Rule Arg 1975 1977 - Apr Sun>=1 0:00 0 - Rule Arg 1985 only - Nov 2 0:00 1:00 S Rule Arg 1986 only - Mar 14 0:00 0 - Rule Arg 1986 1987 - Oct 25 0:00 1:00 S Rule Arg 1987 only - Feb 13 0:00 0 - Rule Arg 1988 only - Feb 7 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. # # 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 Nov -4:16:44 - CMT 1920 May # Cordoba Mean Time -4:00 - ART 1930 Dec -4:00 Arg AR%sT 1969 Oct 5 -3:00 Arg AR%sT 1993 Oct 3 0:00 -3:00 - ART # # Santa Fe (SF), Entre Rios (ER), Corrientes (CN), Misiones (MN), Chaco (CC), # Formosa (FM), La Pampa (LP), Chubut (CH) Zone America/Rosario -4:02:40 - LMT 1894 Nov -4:16:44 - CMT 1920 May -4:00 - ART 1930 Dec -4:00 Arg AR%sT 1969 Oct 5 -3:00 Arg AR%sT 1991 Jul -3:00 - ART # # Cordoba (CB), Santiago del Estero (SE), Salta (SA), Tucuman (TM), La Rioja (LR), San Juan (SJ), San Luis (SL), # Neuquen (NQ), Rio Negro (RN) Zone America/Cordoba -4:16:44 - LMT 1894 Nov -4:16:44 - CMT 1920 May -4:00 - ART 1930 Dec -4:00 Arg AR%sT 1969 Oct 5 -3:00 Arg AR%sT 1990 Jul -3:00 - ART # # Jujuy (JY) Zone America/Jujuy -4:21:12 - LMT 1894 Nov -4:16:44 - 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 6 -4:00 1:00 WARST 1992 Mar 15 -4:00 - WART 1992 Oct 18 -3:00 - ART # # Catamarca (CT) Zone America/Catamarca -4:23:08 - LMT 1894 Nov -4:16:44 - CMT 1920 May -4:00 - ART 1930 Dec -4:00 Arg AR%sT 1969 Oct 5 -3:00 Arg AR%sT 1990 Jul -3:00 - ART 1991 Jul -3:00 Arg AR%sT 1992 Jul -3:00 - ART # # Mendoza (MZ) Zone America/Mendoza -4:35:16 - LMT 1894 Nov -4:16:44 - 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 15 -4:00 1:00 WARST 1992 Mar 1 -4:00 - WART 1992 Oct 18 -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 - LPMT 1931 Oct 15 # La Paz Mean Time -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 Paul Eggert (2000-10-02): # The official decrees referenced below are taken from # <a href="http://pcdsh01.on.br/DecHV.html"> # Decretos sobre o Horario de Verao no Brasil # </a> (1999-10-04, 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. # # These give only one year's rules. After that, the rules are guesses # and are quite possibly wrong, but are more likely than no DST at all. Rule Brazil 2000 max - Oct Sun>=8 0:00 1:00 S Rule Brazil 2001 max - Feb Sun>=15 0:00 0 - # 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. 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 # # 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 # # 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 # # 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 # # Bahia (BA), 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, Mato Grosso do Sul Zone America/Cuiaba -3:44:20 - LMT 1914 -4:00 Brazil AM%sT # # 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 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 (2001-02-20): # I came across a Chilean on-line newspaper, La Tercera. Its # <a href="http://www.tercera.cl/diario/1998/03/13/extras.html"> # 1998-03-13 issue # </a>, says (my translation): # "At 24:00 (midnight) tomorrow (Saturday) - 22:00 in the insular # territory [Easter Island, Juan Fernandez, etc.] - winter time will # begin in the entire country." # From Paul Eggert (2001-02-21): # Assume this rule has been used since DST was introduced in the islands. # 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 1969 1997 - Oct Sun>=9 4:00u 1:00 S Rule Chile 1970 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 # # Whitman says Juan Fernandez Is are like America/Santiago. # San Ambrosio, San Felix # no information; probably 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=2001-03-03-02.24.52.9... # Rule Para 1996 max - 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 max - Mar Sun>=1 0:00 0 - # 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 -5:09 - 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 -4:27:44 - CMT 1912 Feb 12 # Caracas Mean Time -4:30 - VET 1965 # Venezuela Time -4:00 - VET