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 a result of the October 26th, 2022, order from the Mexican Government, Daylight Saving Time (DST) in the United Mexican States will not be observed in 2023 calendar year. In a subsequent order by the Mexican Government, it was declared that Chihuahua, Coahuila, Nuevo León, Tamaulipas and the state of Baja California near the Mexico-U.S. border will continue to honor the DST schedule defined by the United States in 2007 which starts on the second Sunday of March (March 12, 2023) at 2:00 AM and ends on the first Sunday of November (November 5, 2023) at 2:00 AM.
Microsoft will release Windows Updates in support of these DST changes for Mexico as follows:
- A new time zone, America/Ciudad_Juarez, will be created, splitting from the existing time zone America/Ojinaga.
- Clocks in the border municipalities of Janos, Ascensión, Juárez, Praxedis G. Guerrero, and Guadalupe will follow the America/Ciudad_Juarez time zone and will move forward by an hour at 2:00 a.m. on March 12, 2023 to UTC-6 (MDT).
- Clocks in the border municipalities of Ojinaga, Manuel Benavides, and Coyame will follow the the America/Ojinaga time zone and will move forward by an hour at 2:00 a.m. on March 12, 2023 to UTC-5 (CDT).
- Clocks for all states except Baja California, Coahuila de Zaragoza, Nuevo León, Tamaulipas, and Chihuahua will not move forward by an hour at 2:00 a.m. on April 02, 2023.
These changes will appear in the February 2023 Cumulative Update preview for the following Windows versions:
- Windows 10, version 20H2
- Windows 10, version 21H2
- Windows 10, version 22H2
- Windows 11, version 21H2
- Windows 11, version 22H2
All other supported Windows versions will receive the update as part of March 2023 monthly quality update.
Here are the KB article numbers that contain the Mexico DST fix for different versions of Windows:
We have refrained from adding a new time zone to Windows to avoid compatibility issues. There are functions in ICU, etc. to map between IANA and Windows zones; most of these implementations are legacy and cannot pick up any new mappings. After evaluating several options, we felt repurposing existing time zones would be a better approach. Here is a table to help you map between the IANA Zones and the corresponding Windows zones to help you pick the right zone for your machines.
|
Windows Display Name
|
Windows Time Zone ID
|
DST
|
IANA Zone
|
|
(UTC-06:00) Central Time (US & Canada)
|
Central Standard Time |
US DST
|
America/Matamoros
|
|
US DST
|
America/Ojinaga
|
|
(UTC-06:00) Guadalajara, Mexico City, Monterrey
|
Central Standard Time (Mexico)
|
No DST
|
America/Monterrey
|
|
America/Mexico_City
|
|
America/Chihuahua
|
|
America/Bahia_Banderas
|
|
America/Merida
|
|
(UTC-05:00) Chetumal
|
Eastern Standard Time (Mexico)
|
No DST
|
America/Cancun
|
|
(UTC-07:00) Mountain Time (US & Canada)
|
Mountain Standard Time
|
US DST
|
*America/Ciudad_Juarez* (New Zone)
|
|
(UTC-07:00) La Paz, Mazatlan
|
Mountain Standard Time (Mexico)
|
No DST
|
America/Mazatlan
|
|
(UTC-08:00) Baja California
|
Pacific Standard Time (Mexico)
|
US DST
|
America/Tijuana
|
|
(UTC-07:00) Arizona
|
US Mountain Standard Time
|
No DST
|
America/Hermosillo
|
Note: We are unable to provide time-zone mapping at the municipality level for regions that follow multiple DST rules. Hence, please pick the best time zone from the table above. For example, organizations in Anahuac looking to manually map to the right time zone in Anahuac should choose the time zone (UTC -06:00) Central Time (US & Canada).
For Microsoft's official policy on DST and time zone changes, please see Daylight saving time help and support. For information on how to update Windows to use the latest global time zone rules, see How to configure daylight saving time for Microsoft Windows operating systems.
