Mexico time zone history
Mexico has 12 zones of its own in the tz database. Standard times run from UTC−8 (Tijuana) to UTC−5 (Cancún), a spread of 3 hours. Four of the 12 zones still change clocks for summer time under the current rules; the other 8 do not. The Cancún zone has changed standard time most often since 1970: 5 times.
The 12 zones of Mexico since 1970
Zones at a glance
| Zone | Area covered | Standard time | Clock changes today | New standard times since 1970 |
|---|---|---|---|---|
| Cancún | Quintana Roo | UTC−5 | no, last in 2014 | 5 |
| Bahía de Banderas | Bahía de Banderas | UTC−6 | no, last in 2022 | 1 |
| Chihuahua | Chihuahua (most areas) | UTC−6 | no, last in 2022 | 2 |
| Matamoros | Coahuila, Nuevo León and Tamaulipas (US border) | UTC−6 | yes | 0 |
| Mexico City | Central Mexico | UTC−6 | no, last in 2022 | 0 |
| Monterrey | Durango; Coahuila, Nuevo León and Tamaulipas (most areas) | UTC−6 | no, last in 2022 | 0 |
| Mérida | Campeche and Yucatán | UTC−6 | no, last in 2022 | 2 |
| Ojinaga | Chihuahua (US border, east) | UTC−6 | yes | 2 |
| Ciudad Juárez | Chihuahua (US border, west) | UTC−7 | yes | 3 |
| Hermosillo | Sonora | UTC−7 | no, last in 1998 | 0 |
| Mazatlan | Baja California Sur, Nayarit (most areas), Sinaloa | UTC−7 | no, last in 2022 | 0 |
| Tijuana | Baja California | UTC−8 | yes | 0 |
What sets each zone apart
- Cancún: The Cancún zone has changed its standard time 5 times since 1970, the most of the 12 zones in Mexico. Daylight saving time was used in 19 years since 1970, last in 2014; under the current rules the clocks no longer change.
- Bahía de Banderas: 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 at Bahía de Banderas run 1 hour 1 minute ahead of local mean solar time, the second-largest gap of the 10 zones in Mexico whose clocks run ahead of the sun.
- Chihuahua: 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 at Chihuahua run 1 hour 4 minutes ahead of local mean solar time, the largest gap of the 10 zones in Mexico whose clocks run ahead of the sun.
- Matamoros: Standard time has stayed at UTC−6 since 1921, the longest run of the 6 zones in Mexico with no change of standard time since 1970.
- Mexico City: Daylight saving time was used in 27 years since 1970, last in 2022; under the current rules the clocks no longer change.
- Monterrey: Daylight saving time was used in 28 years since 1970, last in 2022; under the current rules the clocks no longer change.
- Mérida: Daylight saving time was used in 27 years since 1970, last in 2022; under the current rules the clocks no longer change.
- Ojinaga: Seasonal clock changes began only in 1996 and are still in use. On October 30, 2022 the summer offset, UTC−6, became permanent standard time; the clocks did not move that day.
- Ciudad Juárez: The latest change of standard time came on November 30, 2022, from UTC−6 to UTC−7. Seasonal clock changes began only in 1996 and are still in use.
- Hermosillo: Hermosillo kept local mean time (UTC−7:23:52) until 1921, tied for the latest switch among the 11 zones on UTC−7 standard time with local mean time in the record. Daylight saving time was used in 3 years since 1970, last in 1998; under the current rules the clocks no longer change.
- Mazatlan: 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.
- Tijuana: Clocks have been changed 114 times since 1970, the most of the 12 zones in Mexico.
How the zones compare with Mexico City since 1970
- Cancún: same time as Mexico City except 3,347 days in 1981–1983, 1997, 1998 and 2015–2026; 1 hour ahead today.
- Mérida: same time as Mexico City except 311 days in 1981 and 1982.
- Monterrey: same time as Mexico City except 210 days in 1988.
- Matamoros: same time as Mexico City except 1,561 days in 1988 and 2010–2026.
- Chihuahua: same time as Mexico City except 8,973 days in 1998–2022.
- Ciudad Juárez: same time as Mexico City except 9,122 days in 1998–2026; 1 hour behind today.
- Ojinaga: same time as Mexico City except 9,533 days in 1998–2026.
- Mazatlan: usually 1 hour behind Mexico City; different on 2 days in 1996–2022.
- Bahía de Banderas: usually 1 hour behind Mexico City; different on 6,117 days in 1996–2026; same time today.
- Hermosillo: usually 1 hour behind Mexico City; different on 4,913 days in 1996–2022.
- Tijuana: usually 2 hours behind Mexico City; different on 6,588 days in 1970–2026.
Daylight saving periods shared by 3 zones since 1970
Mazatlan, Mexico City and Mérida have changed their clocks on the same days since 1970. Times are local clock times before each change.
| Years | Clocks go forward | Clocks go back | Shift and labels |
|---|---|---|---|
| 1996–2000 | first Sunday in April, 02:00 | last Sunday in October, 02:00 | 1 hour |
| 2001 | May 6 | September 30 | 1 hour |
| 2002–2022 | first Sunday in April, 02:00 | last Sunday in October, 02:00 | 1 hour |
Every change of standard time since 1970
15 changes across the 12 zones, oldest first.
- December 26, 1981 Cancún: UTC−6 to UTC−5
- December 26, 1981 Mérida: UTC−6 to UTC−5
- November 2, 1982 Mérida: UTC−5 to UTC−6
- January 4, 1983 Cancún: UTC−5 to UTC−6
- October 26, 1997 Cancún: summer offset kept as standard time
- April 5, 1998 Chihuahua: summer offset kept as standard time
- April 5, 1998 Ciudad Juárez: summer offset kept as standard time
- April 5, 1998 Ojinaga: summer offset kept as standard time
- August 2, 1998 Cancún: UTC−5 to UTC−6
- April 4, 2010 Bahía de Banderas: UTC−7 to UTC−6
- February 1, 2015 Cancún: UTC−6 to UTC−5
- October 30, 2022 Chihuahua: summer offset kept as standard time
- October 30, 2022 Ciudad Juárez: summer offset kept as standard time
- October 30, 2022 Ojinaga: summer offset kept as standard time
- November 30, 2022 Ciudad Juárez: UTC−6 to UTC−7
Clock changes in 2026, 2027 and 2028
Ciudad Juárez, Matamoros, Ojinaga, Tijuana
March 8, 2026 (forward 1 hour); November 1, 2026 (back 1 hour); March 14, 2027 (forward 1 hour); November 7, 2027 (back 1 hour); March 12, 2028 (forward 1 hour); November 5, 2028 (back 1 hour)