Daylight saving time in Mexico
Mexico adopted DST nationwide in 1996, even in its tropical regions, because of its increasing economic ties to the United States. Although the United States has changed the schedule for DST beginning in 2007, only the municipalities located less than 20 kilometers from the USA border go along with it. Daylight saving time for Mexico begins the first Sunday of April, and ends last Sunday of October; and is usually referred to as the "Summer Schedule" (Horario de Verano).
In December 2009, Congress gave permission to the municipalities located less than 20 kilometers from the US border to synchronize their time to that of their US counterparts, resulting in these municipalities joining and leaving DST at the same time as the United States, relieving some border problems and confusion.
- Matamoros, Tamaulipas
- Reynosa, Tamaulipas
- Nuevo Laredo, Tamaulipas
- Anáhuac, Nuevo León
- Acuña, Coahuila
- Piedras Negras, Coahuila
- Ojinaga, Chihuahua
- Juárez, Chihuahua
- Mexicali, Baja California
- Tijuana, Baja California
Apart from the border municipalities (above), daylight saving time for Mexico begins the first Sunday of April, and ends last Sunday of October.
The Marías Islands and the Revillagigedo Archipelago do not observe DST. The westernmost island of the Revillagigedo Archipelago, Clarion Island, uses UTC-8 (PST) all the time; thus, during DST, Mexico has 4 different time zones.
- Official web of the Electric Savings Fiduciary(Fideicomiso del Ahorro de Energia) of the Mexican Federal Electricity Commission 
- Daylight saving time by country