Daylight Saving Time 2011 will end on the first Sunday of November when most of the residents in the United States must turn clocks backward one hour, according to the U.S. National Institute of Standards and Technology.

Time reverts to standard time at 2 a.m. on Sunday November 6th, as established by the Energy Policy Act of 2005. This year, the Daylight Saving Time began in March 13."

We advance our clocks ahead one hour at the beginning of DST, and move them back one hour ("spring forward, fall back") when we return to Standard Time (ST)," the NIST notes.

Daylight Saving Time -- for the U.S. and its territories -- is not observed in Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands, and by most of Arizona (with the exception of the Navajo Indian Reservation in Arizona).