[tz] America/Mexico_City incorrect DST end time for 2018.

Paul Eggert eggert at cs.ucla.edu
Fri Dec 28 17:49:20 UTC 2018

demxic wrote:
> I am sorry I cannot still confirm this issue, I have sent an email to
> Mexico´s CETRAM and I am waiting for an official response.

Thanks for following up on this. It would be helpful to know:

* Does the 03:00->02:00 transition occur only in Mexico City, or do other parts 
of the country also have a 03:00->02:00 transition instead of 02:00->01:00?

* If the transition was 02:00->01:00 in previous years, what was the first year 
that Mexico City switched to the new rules that use 03:00->02:00?

* What is the official law or regulation that specifies the transition times?

I'm asking because the most recent national decree that I can see is here:


It's dated 2017-04-28 and says "a aplicación de este horario estacional surtirá 
efecto desde las dos horas del segundo domingo de marzo y concluirá a las dos 
horas del primer domingo de noviembre", which makes it sound like the fall 
transition should be 02:00->01:00 - unless that "dos horas" means 02:00 
*standard* time instead of 02:00 *current* time, a possible but unusual 
interpretation that I would normally expect to be spelled out.

Although I found several news sources saying there was a 03:00->02:00 transition 
this fall, I also found some saying that the transition was 02:00->01:00:



so it appears at the least that there is some confusion here.

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