Mazatlan 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. Mazatlan kept local mean time (UTC−7:05:40) until 1921, tied for the latest switch among the 11 zones on UTC−7 standard time with local mean time in the record.
UTC−7
Standard time is UTC−7 (MST) 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 | |||
| December 31, 1921 | Local mean time (UTC−7:05:40) 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 |
| April 24, 1942 | Standard time back 1 hour | UTC−7 | MST |
Daylight saving periods
| Years | Clocks go forward | Clocks go back | Shift and labels |
|---|---|---|---|
| 1931 | April 30 | October 1 | 1 hour, MST to MDT |
Since 1970: the periods shared by 3 of 12 zones, listed on the Mexico page.
Also on UTC−7
Hermosillo (Mexico), Ciudad Juárez (Mexico), Phoenix (United States), Denver (United States), Boise (United States), Vancouver (Canada), Dawson Creek (Canada), Fort Nelson (Canada), Whitehorse (Canada) and Cambridge Bay (Canada) (nearest first; 1 more on the list of offsets).
Clocks next door since 1970
- Bahía de Banderas (294 km): same time except 6,115 days in 2010–2026; 1 hour ahead today.
- Chihuahua (603 km): usually 1 hour ahead; different on 8,974 days in 1996–2022.
- Monterrey (675 km): usually 1 hour ahead; different on 212 days in 1988 and 1996–2022.
- Ojinaga (734 km): usually 1 hour ahead; different on 9,534 days in 1996–2026.
- Hermosillo (793 km): same time except 4,913 days in 1999–2022.
How it compares
Standard time has stayed at UTC−7 since 1942.
On standard time, clocks in Mazatlan run 6 minutes ahead of local mean solar time.