Daylight Savings Time officially begins Sunday, March 9, in effect postponing sunset for one hour each day.To participate, set your clock ahead (spring ahead) one hour before going to bed Saturday night.
The semi-controversial program occurs every spring. In the fall, clocks are set back one hour (fall back).
Daylight savings time is optional for the 50 states. Arizona and Hawaii refuse to participate. Proponents say it gives workers another hour to be outdoors in the evening, boosting the economy and saving electrical costs.
During World War II, the U.S. made daylight saving time mandatory as a way to save wartime resources, according to a recent report in National Georgraphic. From 1942-45, DST was observed year-round.
During the 1973-74 Arab oil embargo, the U.S. once again extended daylight saving time through the winter, resulting in a one percent decrease in the country's electrical load, according to federal studies cited by computer scientist David Prerau, author of the book Seize the Daylight: The Curious and Contentious Story of Daylight Saving Time.