Clocks go forward one hour on Sunday, March 9, which is the beginning of Daylight Saving Time (DST). What is daylight saving time (DST)? Daylight saving time (DST) is the part of the year when we advance our clocks by one hour, shifting the time of day in relation to where the Sun is above Earth. In other words, during DST the daylight begins an hour later in the morning and lasts an hour longer in the evening. This change helps keep the hours of daylight coordinated with the time that most people are active. Proponents feel that this saves energy because in the spring and summer months more people may be outside in the evening and not using energy at home. There are, however, ongoing debates about how much energy is saved. The California Energy Commission has additional information about DST and links to several studies about its effects on energy consumption. -------------------------------------------------------------------------------- When is daylight saving time (DST)? Daylight saving time (DST) begins each year on the second Sunday in March at 2 a.m. (local time). Clocks must be moved ahead one hour when DST goes into effect. The changeover back to standard time (ST) occurs on the first Sunday in November at 2 a.m. (local time). Clocks must be moved back one hour. Some people remember which way to move their clocks using the phrase, spring forward, fall back. -------------------------------------------------------------------------------- Who follows daylight saving time and how is it regulated? Most of the United States follows daylight saving time, but a few regions do not. Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands and most of Arizona do not observe DST. In Arizona, the Navajo Indian territories do observe DST. Historically, local jurisdictions were allowed to decide when they would locally switch to DST, or not to observe DST at all. The Uniform Time Act of 1966 defined the rules for the dates of DST and all regions that practice DST use the same transition days. However, that same bill allows states to legislatively decide whether to practice it or not. Also, the date rules sometimes change, most recently in 1986 and 2007, extending the length of DST. The Department of Transportation (and not NIST) oversees and regulates DST. -------------------------------------------------------------------------------- nist.gov/pml/div688/localtime.cfm
Posted on: Thu, 06 Mar 2014 16:00:01 +0000
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