Beginning in 2007, most of the United States begins Daylight Saving Time at 2:00 a.m. on the second Sunday in March and reverts to standard time on the first Sunday in November. In the U.S., each time zone switches at a different time.
Actually, the reasoning behind the change is to save energy. True Story! This year we don't change our clocks back one hour until 2am on November 4th!