Time Zones changes in Argentina
Paul Eggert
eggert at twinsun.com
Wed Jan 23 06:10:48 UTC 2002
Thanks for your letter. The tz files acquired some incorrect data
about Argentine time from the 3rd edition of Shanks's International Atlas.
I now see that the 5th edition corrects this; I'd missed this earlier.
>From what I understand, here are the changes that I think need making
with respect to Argentine time.
* No DST was observed from mid-1974 through mid-1988.
* 1966/1967 DST ended on 1967-04-02, not 1967-04-01.
* Argentine standard time was introduced 1894-10-31, not 1894-11-01.
* Argentine standard time from 1894-10-31 through 1920-04-30 was
-4:16:48.25, not -4:16:44.
* Rosario and Cordoba have the same time zone history since 1970,
so we should mark the America/Rosario Zone as obsolescent.
* Many of the transition dates in 1991 and 1992 are incorrect.
If you see any problems with these changes, please let me know.
It appears that there was widespread disagreement about the clocks in
Argentina in 1991 and 1992. Shanks also indicates that we may need up
to six more regions in Argentina, as he makes the following additional
claims:
- 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 03:00 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.
However, his claims are a bit odd, and his data about this confusing
area seem to peter out around 1992 even though the book was published
in 1999. I think I'll defer adding Zones for each of these regions
until we get more info.
If you're interested, here is the draft of some revised tables for
Argentina. I'll included these in my next proposed patch.
# 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
Rule Arg 1989 1993 - Mar Sun>=1 0:00 0 -
Rule Arg 1989 1992 - Oct Sun>=15 0:00 1:00 S
Rule Arg 1999 only - Oct Sun>=1 0:00 1:00 S
Rule Arg 2000 only - Mar Sun>=1 0:00 0 -
# 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)
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
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