When does Daylight Saving Time/Standard Time begin?
Standard Time begins each year at 2 a.m. on the first Sunday of November. Move your clocks back one hour at the resumption of Standard Time.
Daylight Saving Time begins each year at 2 a.m. on the second Sunday of March. Move clocks ahead one hour at the start of Daylight Saving Time.
Daylight Saving Time and time zones are regulated by the U.S. Department of Transportation, not by NIST.
In 2011, Daylight Saving Time is from 2:00 a.m. (local time) on March 13 until 2:00 a.m. (local time) on November 6.
For more information about Daylight Saving Time rules see: Information about the Current Daylight Saving Time (DST) Rules. The link also provides information on updating clocks on computers using older operating systems that may be using outdated DST rules.
NIST provides accurate official U.S. time through a number of methods. You can get the official U.S. time for your time zone on the web at www.nist.gov, through NIST radio broadcasts automatically setting radio-controlled timepieces to official U.S. time (WWVB Radio Controlled Clocks), and through other NIST time and frequency services.