Daylight saving time (DST) in the United States is the practice of setting the clock forward by one hour during the warmer part of the year, so that evenings have more daylight and mornings have less. All but two states in the USA currently observe DST, the exceptions being Arizona (except for the Navajo Nation, which does observe daylight saving time) and Hawaii.

The overseas territories of American Samoa, Guam, the Northern Mariana Islands, Puerto Rico and the United States Virgin Islands also do not observe DST.

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