Mexico City time zone history
Daylight saving time was used in 27 years since 1970, last in 2022; under the current rules the clocks no longer change. On standard time, clocks in Mexico City run 37 minutes ahead of local mean solar time.
UTC−6
Standard time is UTC−6 (CST) all year under the current rules.
Summer time in 27 of 57 years since 1970
Before 1970
Standard time changes
| Date | Change | New standard time | Clock label |
|---|---|---|---|
| Before 1970 | |||
| January 1, 1922 | Local mean time (UTC−6:36:36) replaced | UTC−7 | MST |
| June 10, 1927 | Standard time forward 1 hour | UTC−6 | CST |
| November 15, 1930 | Standard time back 1 hour | UTC−7 | MST |
| April 1, 1932 | Standard time forward 1 hour | UTC−6 | CST |
Daylight saving periods
| Years | Clocks go forward | Clocks go back | Shift and labels |
|---|---|---|---|
| 1931 | April 30 | October 1 | 1 hour, MST to MDT |
| 1939 | February 5 | June 25 | 1 hour, CST to CDT |
| 1940 | December 9 | not that year | 1 hour, CST to CDT |
| 1941 | not that year | April 1 | 1 hour, CST to CDT |
| 1943 | December 16 | not that year | 1 hour, CST to CWT |
| 1944 | not that year | May 1 | 1 hour, CST to CWT |
| 1950 | February 12 | July 30 | 1 hour, CST to CDT |
Since 1970: the periods shared by 3 of 12 zones, listed on the Mexico page.
Also on UTC−6
Bahía de Banderas (Mexico), Monterrey (Mexico), Matamoros (Mexico), Mérida (Mexico), Guatemala, Belize, El Salvador, Chihuahua (Mexico), Ojinaga (Mexico) and Honduras (nearest first; 17 more on the list of offsets).
Clocks next door since 1970
- Bahía de Banderas (656 km): usually 1 hour behind; different on 6,117 days in 1996–2026; same time today.
- Monterrey (707 km): same time except 210 days in 1988.
- Matamoros (735 km): same time except 1,561 days in 1988 and 2010–2026.
- Mazatlan (864 km): usually 1 hour behind; different on 2 days in 1996–2022.
- Mérida (1,010 km): same time except 311 days in 1981 and 1982.
How it compares
Standard time has stayed at UTC−6 since 1932.