Currently, daylight time begins in the United States on the first Sunday in April and ends on the last Sunday in October. On the first Sunday in April, clocks are set ahead one hour at 2:00 a.m. local standard time, which becomes 3:00 a.m. local daylight time. On the last Sunday in October, clocks are set back one hour at 2:00 a.m. local daylight time, which becomes 1:00 a.m. local standard time.
These dates were recently modified with the passage of the Energy Policy Act of 2005, Pub. L. no. 109-58, 119 Stat 594 (2005). Starting in March 2007, daylight time in the United States will begin on the second Sunday in March and end on the first Sunday in November.
Not all places in the U.S. observe daylight time. In particular, Hawaii and most of Arizona do not use it. Indiana just recently adopted the use of it beginning in 2006.
In 2006, daylight time begins on April 2 and ends on October 29.
In 2007, daylight time begins on March 11 and ends on November 4.
[New law goes into effect.]