America/Mexico_City incorrect DST end time for 2018.
I would like to draw your attention to the fact that Mexico's City Daylight time ended on October 28 2018 03:00 AM local time. That is the exact moment when clocks moved backward to 02:00 AM. Somehow your database marks DST end at 02:00 AM moving clocks backward to 01:00 AM. Please note that this is incorrect. Is it possible to correct for this? -- *My country is the world and my religion is to do good. *Thomas Paine
demxic wrote:
I would like to draw your attention to the fact that Mexico's City Daylight time ended on October 28 2018 03:00 AM local time. That is the exact moment when clocks moved backward to 02:00 AM.
What's your source for this information? CENAM <https://www.cenam.mx/hora_oficial/> says "el horario de verano inicia el primer domingo de abril a las 2h00 de la mañana, momento en el cual los relojes se adelantan una hora, y termina el último domingo de octubre a las 2h00 de la mañana, instante en el que los relojes se atrasan una hora." This suggests that daylight saving time ends at 02:00, not 03:00.
On 2018-12-25 12:06, Paul Eggert wrote:
demxic wrote:
I would like to draw your attention to the fact that Mexico's City Daylight time ended on October 28 2018 03:00 AM local time. That is the exact moment when clocks moved backward to 02:00 AM.
What's your source for this information? CENAM <https://www.cenam.mx/hora_oficial/> says "el horario de verano inicia el primer domingo de abril a las 2h00 de la mañana, momento en el cual los relojes se adelantan una hora, y termina el último domingo de octubre a las 2h00 de la mañana, instante en el que los relojes se atrasan una hora." This suggests that daylight saving time ends at 02:00, not 03:00.
Very clear in: https://www.gob.mx/cenam/articulos/cuando-termina-el-horario-de-verano Debido a lo anterior, el primer domingo de abril no existe la hora del día entre las 2h00 y las 3h00 de la mañana, puesto que en ese día, una vez que los relojes marcan las 2h00 de la mañana del horario de invierno, deben ser adelantados hasta las 3h00 de la mañana del horario de verano. En contra parte, para el último domingo de octubre existen dos intervalos de tiempo distintos que tienen el mismo valor numérico en cuanto a la hora del día, este intervalo es de la 1h00 a las 2h00 de la mañana. Lo anterior ocurre debido a que una vez que los relojes marcan las 2h00 de la mañana del horario de verano, estos son atrasados una hora para marcar la 1h00 de la mañana del horario de invierno. which Google Translates as: Due to the above, the first Sunday of April there is no time of day between 2:00 and 3:00 in the morning, since on that day, once the clocks mark 2:00 in the morning of the winter schedule, they must be advanced until 3:00 in the morning of summer time. On the other hand, for the last Sunday of October there are two different time intervals that have the same numerical value in terms of time of day, this interval is from 1h00 to 2h00 in the morning. The above occurs because once the clocks mark 2h00 in the morning of the summer time, they are delayed one hour to mark 1h00 in the morning of the winter schedule. -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada This email may be disturbing to some readers as it contains too much technical detail. Reader discretion is advised.
Thank you for your quick response. It seems like CENAM information has not been updated for a while, I cannot find any official source but it was in newspapers all around and I am living in Mexico City and witnessed the change. https://www.marca.com/claro-mx/trending/2018/10/22/5bccfb0a46163fe0528b460d.... Un nuevo cambio de horario <https://www.marca.com/claro-mx/trending/2018/03/19/5aa6066eca4741987d8b456e.html>se avecina. El domingo 28 de octubre entra en vigor el horario de invierno 2018 en México y en el mundo; la buena noticia es que deberás de atrasar tu reloj una hora, ganando sesenta minutos de sueño. El cambio se dará durante la madrugada del domingo, por lo que a las 3 AM los relojes tendrán que ponerse a las 2 AM. El horario de invierno permanecerá vigente hasta el día 7 de abril del 2019. https://noticieros.televisa.com/historia/cambio-horario-invierno-2018-mexico... 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. El mar., 25 de dic. de 2018 a la(s) 13:06, Paul Eggert (eggert@cs.ucla.edu) escribió:
demxic wrote:
I would like to draw your attention to the fact that Mexico's City Daylight time ended on October 28 2018 03:00 AM local time. That is the exact moment when clocks moved backward to 02:00 AM.
What's your source for this information? CENAM <https://www.cenam.mx/hora_oficial/> says "el horario de verano inicia el primer domingo de abril a las 2h00 de la mañana, momento en el cual los relojes se adelantan una hora, y termina el último domingo de octubre a las 2h00 de la mañana, instante en el que los relojes se atrasan una hora." This suggests that daylight saving time ends at 02:00, not 03:00.
-- *My country is the world and my religion is to do good. *Thomas Paine
On 2018-12-28 00:02, demxic wrote:
El mar., 25 de dic. de 2018 a la(s) 13:06, Paul Eggert escribió:
demxic wrote:
I would like to draw your attention to the fact that Mexico's City Daylight time ended on October 28 2018 03:00 AM local time. That is the exact moment when clocks moved backward to 02:00 AM. What's your source for this information? CENAM <https://www.cenam.mx/hora_oficial/> says "el horario de verano inicia el primer domingo de abril a las 2h00 de la mañana, momento en el cual los relojes se adelantan una hora, y termina el último domingo de octubre a las 2h00 de la mañana, instante en el que los relojes se atrasan una hora." This suggests that daylight saving time ends at 02:00, not 03:00. Thank you for your quick response. It seems like CENAM information has not been updated for a while, I cannot find any official source but it was in newspapers all around and I am living in Mexico City and witnessed the change.
How did you witness the change? Did you see clocks being manually reset? When people change clocks may be unrelated to the official timekeeping rules which apply to legal situations, and may differ depending on regulations e.g. the BIVA/BMV stock markets keep US time. Timekeeping in Mexico varies as it follows US zones, dates, and rules near the US border and Mexican zones, dates, and rules farther away; as articles will vary with who writes, where they are based, whether they know enough to write comprehensively or customized for target locations, or may lack knowledge and skip research. The lack of specificity in these articles argues for the latter - a hundred or few words about the time change. If CENAM information has not been updated for a while, perhaps there have been no significant legal changes announced by federal or state governments. The tzdb maintainers are reluctant to base any changes on often vague statements in online articles, requiring at least semi-official press releases with comprehensive details, preferring links to or publications of officially enacted laws or regulations in official gazettes or registers by the responsible timekeeping or standards agency or ministry.
https://www.marca.com/claro-mx/trending/2018/10/22/5bccfb0a46163fe0528b460d.... Un nuevo cambio de horario <https://www.marca.com/claro-mx/trending/2018/03/19/5aa6066eca4741987d8b456e.html>se avecina. El domingo 28 de octubre entra en vigor el horario de invierno 2018 en México y en el mundo; la buena noticia es que deberás de atrasar tu reloj una hora, ganando sesenta minutos de sueño. El cambio se dará durante la madrugada del domingo, por lo que a las 3 AM los relojes tendrán que ponerse a las 2 AM. El horario de invierno permanecerá vigente hasta el día 7 de abril del 2019. 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. -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
This email may be disturbing to some readers as it contains too much technical detail. Reader discretion is advised.
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: http://www.diputados.gob.mx/LeyesBiblio/pdf/Dec_HEEUM_280417.pdf 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: https://vanguardia.com.mx/articulo/todo-lo-que-debes-saber-sobre-el-cambio-d... https://www.6enpunto.mx/bienestar/el-horario-de-invierno-inicia-el-28-de-oct... so it appears at the least that there is some confusion here.
Paul Eggert wrote:
I also found some saying that the transition was 02:00->01:00:
https://vanguardia.com.mx/articulo/todo-lo-que-debes-saber-sobre-el-cambio-d... ... so it appears at the least that there is some confusion here.
To make things even more confusing, an October 2017 article in Vanguardia said the opposite, i.e., that the 2017 transition was 03:00->02:00: https://vanguardia.com.mx/articulo/lo-que-debes-hacer-para-que-el-cambio-de-... So did Vanguardia correct the time this year? or were they correct last year? I suspect that most people in Mexico who set the time by hand, did this the night before (or the morning after). Places like hospitals and airports care more about this sort of thing. I looked for when airports changed, and found announcements like this one: https://www.publimetro.com.mx/mx/noticias/2018/10/22/aeropuerto-capitalino-a... which said that AICM (the main airport in Mexico City) "atrasará una hora todos los relojes en sus pantallas de información de vuelos, el próximo domingo 28 de octubre en punto de las 02:00 horas", which sounds like a 02:00->01:00 switch. Every airport announcement I found was similar. It is curious that so many news stories say there is a 03:00->02:00 transition, though.
participants (3)
-
Brian Inglis -
demxic -
Paul Eggert