For most Americans, daylight saving time begins in 2013 at 2 a.m. on Sunday, March 10, when most states spring forward and daylight saving time resumes.
The federal government doesn’t require U.S. states or territories to observe daylight saving time, which is why residents of Arizona, Hawaii, Puerto Rico, the Virgin Islands, American Samoa, Guam, and the Northern Marianas Islands won’t need to turn back their clocks this weekend.
One of the biggest reasons we change our clocks to Daylight Saving Time (DST) is that it reportedly saves electricity.
Time zones were first used by the railroads in 1883 to standardize their schedules.