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Daylight Saving Time & Time Zone Blog
3 MIN READ

Mexico 2023 time zone updates now available

SharadaRangaraj's avatar
SharadaRangaraj
Icon for Microsoft rankMicrosoft
Feb 22, 2023
Editor's note (3.31.2023): This article has been updated to provide additional clarity and guidance on time-zone mapping, and to include links to the KB articles offering the time zone fix.   As ...
Updated Mar 31, 2023
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mattjohnsonpint's avatar
mattjohnsonpint
Copper Contributor
Mar 05, 2023

Hi SharadaRangaraj.  Thanks for the information, but your blog post appears to refer to the IANA time zone changes only.  After installing the Feb 2023 Win 11 22H2 update, I only see two significant changes in the Windows registry time zone data:

  • The "Mountain Standard Time (Mexico)" zone had its display name changed from "(UTC-07:00) Chihuahua, La Paz, Mazatlan" to "(UTC-07:00) La Paz, Mazatlan", and has a new Dynamic DST entry for 2023.
  • The "Central Standard Time (Mexico)" zone has a new Dynamic DST entry for 2023.

I don't see any new Windows time zones though.  According to policy at https://aka.ms/time, a new zone is required because the state of Chihuahua is a first-order administrative division, and it now no longer has any Windows time zone that correctly reflects both its current time and its distinct history of time.

 

The states of Chihuahua and Sinaloa used to together be represented by "Mountain Standard Time (Mexico)", but that zone only now applies to Sinaloa.  There needs to be a new Windows time zone created for the state of Chihuahua.  I recommend "Chihuahua Standard Time" for the registry key, and "(UTC-06:00) Chihuahua" for the display name.

 

It would also be preferred if another Windows time zone was created specifically for Ciudad Juárez.  Consider that it has a much larger population than the city of Chihuahua, and each now have their own distinct history of time within the state of Chihuahua.  I recommend "Juarez Standard Time" for the registry key, and "(UTC-07:00) Ciudad Juárez" for the display name.

 

Please work to add these time zones to the next Windows update, to comply with MS time policy.

 

I do see that the update picked up the IANA update and associated CLDR changes, which is good. Another CLDR update will have to be coordinated with these new Windows zones.

 

Thank you. 🙂