I have not found any single news item that any political decision has been taken whether to follow in Mexico the new US DST rule (that is a month longer than the old one). After the legal fight between former president Vicente Fox and former Mexico City mayor Manuel Lopez Obrador it was clarified in supreme court that DST issues remain with the Congress. On the page of the Energy Saving Trust of Mexico http://www.fide.org.mx/servicios/verano.html it says that DST (spanish: horario de verano) will start in 2007 Sunday 1.st. of April, and end Sunday 28.th. of October (old US-style DST). In the following page http://www.cenam.mx/HoraExacta.asp there is an explanation of that USA will change their schedule to be from Second Sunday of March at 2:00 until First Sunday of November at 2:00 while Mexico will continue with the old DST that is from First Sunday of April at 2:00 to Last Sunday of October at 2:00. However, I'm willing to bet a dinner on that Mexico will follow US from one of these two scenarios: (a) A hasty just-in-time decision puts Mexico on US DST just before 11.th. of March 2007. (b) Next year, a decision is made to put Mexico on the new US style DST, e.g. starting 9.th. of March 2008. Of course at the moment it looks like Mexico is in good company since Cuba, Haiti and Turks & Caicos Islands will also follow old-style US DST. But that is also a reason to keep a close eye on these countries, which might possibly change to keep it simpler to do business with the US (essentially the argument for Canada to change). I found the page http://www.cddhcu.gob.mx/bibliot/publica/inveyana/polisoc/horver/capitulo5.h tm which belongs to the Mexican Congrees (Camara de Diputados) that mentions the different timezone rules in Mexico since 1921. A fair amount of it corresponds well with the tz database (and therefore with Shanks, I presume) but there are differences. If everything is taken literally, there are at least a need to introduce new timezones for the states Campeche, Tamaulipas, Tabasco+CHS, Baja California Sur, Durango, Veracruz+Oaxaca, and Coahuila. Before I go too far with deciphering this, I would like to hear the general opinion about if this is an authoritative source or not - after all the Congress only recently got authority over timezone issues in Mexico (formally), and this list might have some goofed up details from extracting from old documents by "new" people. It does seem odd that there is no activity between 1948 and 1981. But perhaps we should just rely on Shanks for that period. Particularly I would like Paul Eggert's/David Olson's opinion on this. Regards, - Jesper Jesper Nørgaard Welen Email: jnorgard@Prodigy.Net.mx Project Leader (Líder de Proyecto) Software CIMMYT - Centro Internacional de Mejoramiento de Maíz y Trigo Dirección: CIMMYT Int. c/o Jesper Nørgaard Km. 45, Carretera México-Veracruz El Batán Texcoco, Edo. de México CP 56130 MEXICO Tel.: +52 (55) 58-04-20-04 ext. 1374 Fax: +52 (55) 58-04-75-58 Tel. Casa: 53-10-05-95 ó 53-10-97-78 Download the shareware program World Time Explorer, I made: http://www.worldtimeexplorer.com/index.html
Jesper Norgaard Welen <jnorgard@prodigy.net.mx> writes:
http://www.cddhcu.gob.mx/bibliot/publica/inveyana/polisoc/horver/capitulo5.h...
Yes, that's section 5 of the history of Mexican local time that <http://www.twinsun.com/tz/tz-link.htm> points to.
If everything is taken literally, there are at least a need to introduce new timezones for the states Campeche, Tamaulipas, Tabasco+CHS, Baja California Sur, Durango, Veracruz+Oaxaca, and Coahuila.
Do these states have time zone histories that differ since 1970? If so, we would need new entries for them. (I don't read Spanish well, alas).
Before I go too far with deciphering this, I would like to hear the general opinion about if this is an authoritative source or not - after all the Congress only recently got authority over timezone issues in Mexico (formally), and this list might have some goofed up details from extracting from old documents by "new" people.
That could be, yes. But I'm not really qualified to judge this, unfortunately.
True, I forgot about the 1970 cutoff. Also the decree from March 23, 1989 was immediately revoked March 30, 1989 so it never came into effect. Perhaps we don't need any new timezones. But there are changes anyway in the dates and timezone rules as far as I can see. I will try and elaborate a suggestion of changes to the tz database. I will elaborate it respecting changes on decree dates, but respecting existing changes between decree dates, especially in the gap between 1948 and 1981. These decrees no doubt were issued, and followed. But we have no guarantee that no more decrees exist, hence I want to respect the tz database in between decree dates. Also, if the tz database has one date, and the decree another date close-by, I think we should go with the existing tz date because there is no guarantee that the decree came into effect the date it says, in fact the date given is the date the decree was published in the official "newspaper". Regards, - Jesper Nørgaard Welen -----Original Message----- From: Paul Eggert [mailto:eggert@cs.ucla.edu] Sent: Lunes, 22 de Enero de 2007 0:36 To: tz@lecserver.nci.nih.gov Subject: Re: Mexico DST news Jesper Norgaard Welen <jnorgard@prodigy.net.mx> writes:
http://www.cddhcu.gob.mx/bibliot/publica/inveyana/polisoc/horver/capit ulo5.htm
Yes, that's section 5 of the history of Mexican local time that <http://www.twinsun.com/tz/tz-link.htm> points to.
If everything is taken literally, there are at least a need to introduce new timezones for the states Campeche, Tamaulipas, Tabasco+CHS, Baja California Sur, Durango, Veracruz+Oaxaca, and Tabasco+Coahuila.
Do these states have time zone histories that differ since 1970? If so, we would need new entries for them. (I don't read Spanish well, alas).
Before I go too far with deciphering this, I would like to hear the general opinion about if this is an authoritative source or not - after all the Congress only recently got authority over timezone issues in Mexico (formally), and this list might have some goofed up details from extracting from old documents by "new" people.
That could be, yes. But I'm not really qualified to judge this, unfortunately.
Date: Mon, 22 Jan 2007 23:30:29 -0600 From: Jesper Norgaard Welen <jnorgard@prodigy.net.mx> Message-ID: <!~!UENERkVCMDkAAQACAAAAAAAAAAAAAAAAABgAAAAAAAAADuUZBf7Jo0OrktsA6harmMKAAAAQAAAARpcGUp725EKNvvsLJPnFWwEAAAAA@prodigy.net.mx> | I will elaborate it respecting changes on decree dates, but respecting | existing changes between decree dates, especially in the gap between 1948 | and 1981. [...] I know this might seem a little obvious, but when you find something like you have - a govt site that is setting out what looks to be authoritative data, but which might not be perfect, the best thing to do is probably to find the person who actually created the data, and ask them where it came from. That certainly won't be a politician (or is extremely unlikely to be), but some bureaucrat, or perhaps external researcher. Usually once you find the right person (either an individual, or the real worker for a committee) they'll tell you where their data comes from, and from that, you'll have a much better idea how much trust should be placed upon that data. That you're a member of the international group that documents all things related to timezones will probably help you to actually make contact with the appropriate person, the right approach is likely to be that you're seeking more technical information than is given on the web page. With this, it is important to be aware that the purpose of government documents is almost never to illuminate history (or even to rewrite it, however tempting it is sometimes to assign that as a motive). Their purpose is to keep the people happy with current events and future changes - and since people mostly resist any change, one of the best ways to overcome that is to shoe that the "change" is just something that has happened repeatedly, and so is not a change, but just a regular event... To do that, publishing a history of what has happened in the past can be very useful - but there's no need for such a history to be extremely accurate. If you want to convince people that moving the dates for DST around is not such an unusual event, because it also happened in 1917, and 1943, and ... then you want to explain what happened back then. But to do that they don't need absolute accuracy, which actual day in 1917 a change happened doesn't really matter to anyone, nor for that matter whether it was really 1917 or 1918 or ... They don't need that degree of accuracy, and while they aren't often deliberately false in the statements made, they also have no particular reason do do extensive historical research in order to be precisely correct - if a report can be found that says something happened, that's likely to be good enough, checking the accuracy of the report not really needed (and for their purpose, that's even true). What's more, since nothing nefarious is really happening, and no-one is attempting to lay blame, there's no reason they wouldn't admit that some of the details might be slightly inaccurate if you ask the right person. You do have to find the right person though, others will tell you it must be right because it is written in a govt document, they don't know it is wrong (or where the data originates), so it must be right... kre
participants (3)
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Jesper Norgaard Welen -
Paul Eggert -
Robert Elz