Mexico adopted daylight saving time (Spanish: horario de verano) nationwide in 1996, even in its tropical regions, because of its increasing economic ties to the United States. Although the United States changed the schedule for DST beginning in 2007, only the municipalities located less than 20 km from the border have adopted the change. 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).