From Mariano Absatz (2004-05-21): Today it was officially published that the Province of Mendoza is changing its timezone this winter... starting tomorrow night.... http://www.gobernac.mendoza.gov.ar/boletin/pdf/20040521-27158-normas.pdf From Paul Eggert (2004-05-24): It's Law No. 7,210. This change is due to a public power emergency, so for now we'll assume it's for this year only. From Paul Eggert (2018-01-31): Hora de verano para la República Argentina http://buenasiembra.com.ar/esoterismo/astrologia/hora-de-verano-de-la-republica-argentina-27.html 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 & Pottenger. It is upward compatible with Milne, who says Córdoba time was -4:16:48.2. From Mariano Absatz (2004-06-05): These media articles from a major newspaper mostly cover the current state: http://www.lanacion.com.ar/04/05/27/de_604825.asp http://www.lanacion.com.ar/04/05/28/de_605203.asp The following eight (8) provinces pulled clocks back to UTC-04:00 at midnight Monday May 31st. (that is, the night between 05/31 and 06/01). Apparently, all nine provinces would go back to UTC-03:00 at the same time in October 17th. Catamarca, Chubut, La Rioja, San Juan, San Luis, Santa Cruz, Tierra del Fuego, Tucumán. From Mariano Absatz (2004-06-14): ... this weekend, the Province of Tucumán decided it'd go back to UTC-03:00 yesterday midnight (that is, at 24:00 Saturday 12th), since the people's annoyance with the change is much higher than the power savings obtained.... From Gwillim Law (2004-06-14): http://www.lanacion.com.ar/04/06/10/de_609078.asp ... "The time change in Tierra del Fuego was a conflicted decision from the start. The government had decreed that the measure would take effect on June 1, but a normative error forced the new time to begin three days earlier, from a Saturday to a Sunday.... Our understanding was that the change was originally scheduled to take place on June 1 at 00:00 in Chubut, Santa Cruz, Tierra del Fuego (and some other provinces). Sunday was May 30, only two days earlier. So the article contains a contradiction. I would give more credence to the Saturday/Sunday date than the "three days earlier" phrase, and conclude that Tierra del Fuego set its clocks back at 2004-05-30 00:00. From Steffen Thorsen (2004-10-05): The previous law 7210 which changed the province of Mendoza's time zone back in May have been modified slightly in a new law 7277, which set the new end date to 2004-09-26 (original date was 2004-10-17). http://www.gobernac.mendoza.gov.ar/boletin/pdf/20040924-27244-normas.pdf From Mariano Absatz (2004-10-05): San Juan changed from UTC-03:00 to UTC-04:00 at midnight between Sunday, May 30th and Monday, May 31st. It changed back to UTC-03:00 at midnight between Saturday, July 24th and Sunday, July 25th.... http://www.sanjuan.gov.ar/prensa/archivo/000329.html http://www.sanjuan.gov.ar/prensa/archivo/000426.html http://www.sanjuan.gov.ar/prensa/archivo/000441.html From Alex Krivenyshev (2008-01-17): Here are articles that Argentina Province San Luis is planning to end DST as earlier as upcoming Monday January 21, 2008 or February 2008: Provincia argentina retrasa reloj y marca diferencia con resto del país (Argentine Province delayed clock and mark difference with the rest of the country) http://cl.invertia.com/noticias/noticia.aspx?idNoticia=200801171849_EFE_ET4373&idtel Es inminente que en San Luis atrasen una hora los relojes (It is imminent in San Luis clocks one hour delay) https://www.lagaceta.com.ar/nota/253414/Economia/Es-inminente-que-en-San-Luis-atrasen-una-hora-los-relojes.html http://www.worldtimezone.com/dst_news/dst_news_argentina02.html From Jesper Nørgaard Welen (2008-01-18): The page of the San Luis provincial government http://www.sanluis.gov.ar/notas.asp?idCanal=0&id=22812 confirms what Alex Krivenyshev has earlier sent to the tz emailing list about that San Luis plans to return to standard time much earlier than the rest of the country. It also confirms that upon request the provinces San Juan and Mendoza refused to follow San Luis in this change. The change is supposed to take place Monday the 21st at 0:00 hours. As far as I understand it if this goes ahead, we need a new timezone for San Luis (although there are also documented independent changes in the southamerica file of San Luis in 1990 and 1991 which has not been confirmed). From Jesper Nørgaard Welen (2008-01-25): Unfortunately the below page has become defunct, about the San Luis time change. Perhaps because it now is part of a group of pages "Most important pages of 2008." You can use http://www.sanluis.gov.ar/notas.asp?idCanal=8141&id=22834 instead it seems. Or use "Buscador" from the main page of the San Luis government, and fill in "huso" and click OK, and you will get 3 pages from which the first one is identical to the above. From Mariano Absatz (2008-01-28): I can confirm that the Province of San Luis (and so far only that province) decided to go back to UTC-3 effective midnight Jan 20th 2008 (that is, Monday 21st at 0:00 is the time the clocks were delayed back 1 hour), and they intend to keep UTC-3 as their timezone all year round (that is, unless they change their mind any minute now). So we'll have to add yet another city to 'southamerica' (I think San Luis city is the mos populated city in the Province, so it'd be America/Argentina/San_Luis... of course I can't remember if San Luis's history of particular changes goes along with Mendoza or San Juan :-( (I only remember not being able to collect hard facts about San Luis back in 2004, when these provinces changed to UTC-4 for a few days, I mailed them personally and never got an answer). From Paul Eggert (2014-08-12): Unless otherwise specified, data entries are from Shanks & Pottenger through 1992, from the IATA otherwise. As noted below, Shanks & Pottenger say that America/Cordoba split into 6 subregions during 1991/1992, one of which was America/San_Luis, but we haven't verified this yet so for now we'll keep America/Cordoba a single region rather than splitting it into the other 5 subregions. From Mariano Absatz (2009-03-13): Yesterday (with our usual 2-day notice) the Province of San Luis decided that next Sunday instead of "staying" @utc-03:00 they will go to utc-04:00 until the second Saturday in October... The press release is at http://www.sanluis.gov.ar/SL/Paginas/NoticiaDetalle.asp?TemaId=1&InfoPrensaId=3102 (I couldn't find the decree, but www.sanluis.gov.ar is the official page for the Province Government.) There's also a note in only one of the major national papers ... http://www.lanacion.com.ar/nota.asp?nota_id=1107912 The press release says [quick and dirty translation]: ... announced that next Sunday, at 00:00, Puntanos (the San Luis inhabitants) will have to turn back one hour their clocks Since then, San Luis will establish its own Province timezone. Thus, during 2009, this timezone change will run from 00:00 the third Sunday in March until 24:00 of the second Saturday in October. From Mariano Absatz (2009-10-16): ...the Province of San Luis is a case in itself. The Law at http://www.diputadossanluis.gov.ar/diputadosasp/paginas/verNorma.asp?NormaID=276 is ambiguous because establishes a calendar from the 2nd Sunday in October at 0:00 thru the 2nd Saturday in March at 24:00 and the complement of that starting on the 2nd Sunday of March at 0:00 and ending on the 2nd Saturday of March at 24:00. This clearly breaks every time the 1st of March or October is a Sunday. IMHO, the "spirit of the Law" is to make the changes at 0:00 on the 2nd Sunday of October and March. The problem is that the changes in the rest of the Provinces that did change in 2007/2008, were made according to the Federal Law and Decrees that did so on the 3rd Sunday of October and March. In fact, San Luis actually switched from UTC-4 to UTC-3 last Sunday (October 11th) at 0:00. So I guess a new set of rules, besides "Arg", must be made and the last America/Argentina/San_Luis entries should change to use these... ... From Alexander Krivenyshev (2010-04-09): According to news reports from El Diario de la República Province San Luis, Argentina (standard time UTC-04) will keep Daylight Saving Time after April 11, 2010 - will continue to have same time as rest of Argentina (UTC-3) (no DST). Confirmaron la prórroga del huso horario de verano (Spanish) http://www.eldiariodelarepublica.com/index.php?option=com_content&task=view&id=29383&Itemid=9 or (some English translation): http://www.worldtimezone.com/dst_news/dst_news_argentina08.html From Mariano Absatz (2010-04-12): yes...I can confirm this...and given that San Luis keeps calling UTC-03:00 "summer time", we should't just let San Luis go back to "Arg" rules...San Luis is still using "Western ARgentina Time" and it got stuck on Summer daylight savings time even though the summer is over. From Paul Eggert (2018-01-23): Perhaps San Luis operates on the legal fiction that it is at -04 with perpetual daylight saving time, but ordinary usage typically seems to just say it's at -03; see, for example, https://es.wikipedia.org/wiki/Hora_oficial_argentina We've documented similar situations as being plain changes to standard time, so let's do that here too. This does not change UTC offsets, only tm_isdst and the time zone abbreviations. One minor plus is that this silences a zic complaint that there's no POSIX TZ setting for timestamps past 2038. Zone NAME STDOFF RULES FORMAT [UNTIL] Buenos Aires (BA), Capital Federal (CF),
Attributed Statements:
Mariano Absatz (2004-05-21):
Today it was officially published that the Province of Mendoza is changing its timezone this winter... starting tomorrow night.... http://www.gobernac.mendoza.gov.ar/boletin/pdf/20040521-27158-normas.pdf
Paul Eggert (2004-05-24):
It's Law No. 7,210. This change is due to a public power emergency, so for now we'll assume it's for this year only.
Paul Eggert (2018-01-31):
Hora de verano para la República Argentina http://buenasiembra.com.ar/esoterismo/astrologia/hora-de-verano-de-la-republica-argentina-27.html 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 & Pottenger. It is upward compatible with Milne, who says Córdoba time was -4:16:48.2.
Mariano Absatz (2004-06-05):
These media articles from a major newspaper mostly cover the current state: http://www.lanacion.com.ar/04/05/27/de_604825.asp http://www.lanacion.com.ar/04/05/28/de_605203.asp The following eight (8) provinces pulled clocks back to UTC-04:00 at midnight Monday May 31st. (that is, the night between 05/31 and 06/01). Apparently, all nine provinces would go back to UTC-03:00 at the same time in October 17th. Catamarca, Chubut, La Rioja, San Juan, San Luis, Santa Cruz, Tierra del Fuego, Tucumán.
Mariano Absatz (2004-06-14):
... this weekend, the Province of Tucumán decided it'd go back to UTC-03:00 yesterday midnight (that is, at 24:00 Saturday 12th), since the people's annoyance with the change is much higher than the power savings obtained....
Gwillim Law (2004-06-14):
http://www.lanacion.com.ar/04/06/10/de_609078.asp ... "The time change in Tierra del Fuego was a conflicted decision from the start. The government had decreed that the measure would take effect on June 1, but a normative error forced the new time to begin three days earlier, from a Saturday to a Sunday.... Our understanding was that the change was originally scheduled to take place on June 1 at 00:00 in Chubut, Santa Cruz, Tierra del Fuego (and some other provinces). Sunday was May 30, only two days earlier. So the article contains a contradiction. I would give more credence to the Saturday/Sunday date than the "three days earlier" phrase, and conclude that Tierra del Fuego set its clocks back at 2004-05-30 00:00.
Steffen Thorsen (2004-10-05):
The previous law 7210 which changed the province of Mendoza's time zone back in May have been modified slightly in a new law 7277, which set the new end date to 2004-09-26 (original date was 2004-10-17). http://www.gobernac.mendoza.gov.ar/boletin/pdf/20040924-27244-normas.pdf
Mariano Absatz (2004-10-05):
San Juan changed from UTC-03:00 to UTC-04:00 at midnight between Sunday, May 30th and Monday, May 31st. It changed back to UTC-03:00 at midnight between Saturday, July 24th and Sunday, July 25th.... http://www.sanjuan.gov.ar/prensa/archivo/000329.html http://www.sanjuan.gov.ar/prensa/archivo/000426.html http://www.sanjuan.gov.ar/prensa/archivo/000441.html
Alex Krivenyshev (2008-01-17):
Here are articles that Argentina Province San Luis is planning to end DST as earlier as upcoming Monday January 21, 2008 or February 2008: Provincia argentina retrasa reloj y marca diferencia con resto del país (Argentine Province delayed clock and mark difference with the rest of the country) http://cl.invertia.com/noticias/noticia.aspx?idNoticia=200801171849_EFE_ET4373&idtel Es inminente que en San Luis atrasen una hora los relojes (It is imminent in San Luis clocks one hour delay) https://www.lagaceta.com.ar/nota/253414/Economia/Es-inminente-que-en-San-Luis-atrasen-una-hora-los-relojes.html http://www.worldtimezone.com/dst_news/dst_news_argentina02.html
Jesper Nørgaard Welen (2008-01-18):
The page of the San Luis provincial government http://www.sanluis.gov.ar/notas.asp?idCanal=0&id=22812 confirms what Alex Krivenyshev has earlier sent to the tz emailing list about that San Luis plans to return to standard time much earlier than the rest of the country. It also confirms that upon request the provinces San Juan and Mendoza refused to follow San Luis in this change. The change is supposed to take place Monday the 21st at 0:00 hours. As far as I understand it if this goes ahead, we need a new timezone for San Luis (although there are also documented independent changes in the southamerica file of San Luis in 1990 and 1991 which has not been confirmed).
Jesper Nørgaard Welen (2008-01-25):
Unfortunately the below page has become defunct, about the San Luis time change. Perhaps because it now is part of a group of pages "Most important pages of 2008." You can use http://www.sanluis.gov.ar/notas.asp?idCanal=8141&id=22834 instead it seems. Or use "Buscador" from the main page of the San Luis government, and fill in "huso" and click OK, and you will get 3 pages from which the first one is identical to the above.
Mariano Absatz (2008-01-28):
I can confirm that the Province of San Luis (and so far only that province) decided to go back to UTC-3 effective midnight Jan 20th 2008 (that is, Monday 21st at 0:00 is the time the clocks were delayed back 1 hour), and they intend to keep UTC-3 as their timezone all year round (that is, unless they change their mind any minute now). So we'll have to add yet another city to 'southamerica' (I think San Luis city is the mos populated city in the Province, so it'd be America/Argentina/San_Luis... of course I can't remember if San Luis's history of particular changes goes along with Mendoza or San Juan :-( (I only remember not being able to collect hard facts about San Luis back in 2004, when these provinces changed to UTC-4 for a few days, I mailed them personally and never got an answer).
Paul Eggert (2014-08-12):
Unless otherwise specified, data entries are from Shanks & Pottenger through 1992, from the IATA otherwise. As noted below, Shanks & Pottenger say that America/Cordoba split into 6 subregions during 1991/1992, one of which was America/San_Luis, but we haven't verified this yet so for now we'll keep America/Cordoba a single region rather than splitting it into the other 5 subregions.
Mariano Absatz (2009-03-13):
Yesterday (with our usual 2-day notice) the Province of San Luis decided that next Sunday instead of "staying" @utc-03:00 they will go to utc-04:00 until the second Saturday in October... The press release is at http://www.sanluis.gov.ar/SL/Paginas/NoticiaDetalle.asp?TemaId=1&InfoPrensaId=3102 (I couldn't find the decree, but www.sanluis.gov.ar is the official page for the Province Government.) There's also a note in only one of the major national papers ... http://www.lanacion.com.ar/nota.asp?nota_id=1107912 The press release says [quick and dirty translation]: ... announced that next Sunday, at 00:00, Puntanos (the San Luis inhabitants) will have to turn back one hour their clocks Since then, San Luis will establish its own Province timezone. Thus, during 2009, this timezone change will run from 00:00 the third Sunday in March until 24:00 of the second Saturday in October.
Mariano Absatz (2009-10-16):
...the Province of San Luis is a case in itself. The Law at http://www.diputadossanluis.gov.ar/diputadosasp/paginas/verNorma.asp?NormaID=276 is ambiguous because establishes a calendar from the 2nd Sunday in October at 0:00 thru the 2nd Saturday in March at 24:00 and the complement of that starting on the 2nd Sunday of March at 0:00 and ending on the 2nd Saturday of March at 24:00. This clearly breaks every time the 1st of March or October is a Sunday. IMHO, the "spirit of the Law" is to make the changes at 0:00 on the 2nd Sunday of October and March. The problem is that the changes in the rest of the Provinces that did change in 2007/2008, were made according to the Federal Law and Decrees that did so on the 3rd Sunday of October and March. In fact, San Luis actually switched from UTC-4 to UTC-3 last Sunday (October 11th) at 0:00. So I guess a new set of rules, besides "Arg", must be made and the last America/Argentina/San_Luis entries should change to use these... ...
Alexander Krivenyshev (2010-04-09):
According to news reports from El Diario de la República Province San Luis, Argentina (standard time UTC-04) will keep Daylight Saving Time after April 11, 2010 - will continue to have same time as rest of Argentina (UTC-3) (no DST). Confirmaron la prórroga del huso horario de verano (Spanish) http://www.eldiariodelarepublica.com/index.php?option=com_content&task=view&id=29383&Itemid=9 or (some English translation): http://www.worldtimezone.com/dst_news/dst_news_argentina08.html
Mariano Absatz (2010-04-12):
yes...I can confirm this...and given that San Luis keeps calling UTC-03:00 "summer time", we should't just let San Luis go back to "Arg" rules...San Luis is still using "Western ARgentina Time" and it got stuck on Summer daylight savings time even though the summer is over.
Paul Eggert (2018-01-23):
Perhaps San Luis operates on the legal fiction that it is at -04 with perpetual daylight saving time, but ordinary usage typically seems to just say it's at -03; see, for example, https://es.wikipedia.org/wiki/Hora_oficial_argentina We've documented similar situations as being plain changes to standard time, so let's do that here too. This does not change UTC offsets, only tm_isdst and the time zone abbreviations. One minor plus is that this silences a zic complaint that there's no POSIX TZ setting for timestamps past 2038. Zone NAME STDOFF RULES FORMAT [UNTIL] Buenos Aires (BA), Capital Federal (CF),
southamerica(Lines 198 to 401)