Established by the Energy Policy Act of 2005, Pub. L. no. 109-58, 119 Stat 594 (2005)…
In the United States of America the state of Hawaii, and most of Arizona, do not use it.
Daylight (savings) time begins on the second Sunday in March (and ends on the first Sunday in November).
On the second Sunday in March, at 2:00 a.m. local standard time, clocks are set ahead one hour. (On the first Sunday in November, at 2:00 a.m. local daylight time, clocks are set back one hour.)
* In 2009, daylight time begins on March 8 and ends on November 1.