Most of Mexico is on Hora del Centro (GMT/UTC minus six hours). Six northern and western states are on GMT/UTC minus seven or eight hours, while one eastern state is on GMT/UTC minus five hours. Daylight savings applies in most of Mexico from April to October.
Hora del Centro The same as CST (US Central Time; GMT minus six hours in winter, and GMT minus five hours during daylight saving), this time zone applies to most of Mexico, including Campeche, Chiapas, Tabasco and Yucatán.
Hora de las Montañas The same as MST (US Mountain Time; GMT minus seven hours in winter, GMT minus six hours during daylight saving), this time zone applies to five northern and western states in Mexico – Chihuahua, Nayarit, Sinaloa, Sonora and Baja California Sur.
Hora del Pacífico The same as PST (US Pacific Time; GMT minus eight hours in winter, GMT minus seven hours during daylight saving), this time zone applies to Baja California Norte.
The state of Quintana Roo observes US Eastern Standard Time (GMT minus five hours year-round).
Daylight saving time (horario de verano; summer time) in nearly all of Mexico runs from the first Sunday in April to the last Sunday in October. Clocks go forward one hour in April and back one hour in October. Exceptions to the general rule:
- The northwestern state of Sonora ignores daylight saving (like its US neighbor Arizona), as does Quintana Roo, so they remain on MST all year.
- Ten cities on or near the US border – Ciudad Acuña, Ciudad Anahuac, Ciudad Juárez, Matamoros, Mexicali, Nuevo Laredo, Ojinaga, Piedras Negras, Reynosa and Tijuana – change their clocks on the second Sunday in March and the first Sunday in November to synchronize with US daylight-saving periods.