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.