The Department of Transportation reminds that Daylight Saving Time will begin this Sunday, March 9, with clocks being set ahead one hour for most Americans.
Daylight time was observed starting in April through October, prior to legislation that took effect last year in an effort to reduce energy consumption.
Federal law does not require observance daylight time, but those that do must follow the starting and ending dates as set by the law.
No resetting of clocks is required for those parts of the country not observing daylight saving time, including the states of Arizona and Hawaii, and territories of Puerto Rico, the Virgin Islands, American Samoa, Guam and the Northern Marianas.
The four primary U.S. time zones were created in 1883 as a way to manage transcontinental rail traffic. Responsibility over them and daylight saving time was given to the Interstate Commerce Commission, until 1967, when dominion was given to DOT.