Daylight saving time in the Americas

Daylight saving time in the Americas is the arrangement in the Americas by which clocks are advanced by one hour in spring and moved back in autumn, to make the most of seasonal daylight. The practice is widespread in North America, with most of Canada, Mexico and the United States participating, but much less so in South America.

Canada, Mexico and the United States use Daylight saving time on a wide scale, with only a few states/provinces and parts thereof opting out of the practice or adopting it year-round without the twice yearly switch.

The United States territory of Puerto Rico adopted DST through legislation passed in 2000 but, after a change in governors, dropped it in 2001, three days before it would have gone into effect.

Since 2007, in areas of Canada and United States in which it is used, daylight saving time begins on the second Sunday of March and ends on the first Sunday of November. In Mexico, Congress has consistently been refusing to adopt this schedule on a nationwide basis for nearly a decade. Therefore, only certain border cities in Mexican states that observe DST follow the same pattern as Canada and the United States. The rest of Mexico remains out of phase beginning DST on the first Sunday of April and ending on the last Sunday of October, the same schedule followed by Canada and the United States prior to 2007.

Saint Pierre and Miquelon, located near the Canadian coast, belongs to France, but observes daylight saving time according to Canadian rules.

Greenland (excluding two minor areas at Danmarkshavn and Pituffik) observes DST and uses the European convention (DST begins 01:00 UTC last Sunday in March and ends 01:00 UTC last Sunday in October). Most populated places in the country are in the UTC−3 zone in the winter (UTC−2 in the summer). Because of this, with respect to local time, clocks are changed from 22:00 to 23:00 in the spring (on the Saturday before the last Sunday in March), and reset back from 23:00 to 22:00 in the autumn (on the Saturday before the last Sunday in October).

Danmarkshavn does not use DST, because it is a weather station with an airstrip which is supplied from Iceland, which does not use DST. This might apply to some other weather station in the area.

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