Daylight Saving Time

Daylight Saving Time

Also called summer time, daylight saving time is a system for uniformly advancing clocks, especially in summer, so as to extend daylight hours during conventional waking time. In the Northern Hemisphere, clocks are usually set ahead one hour in late March or in April and are set back one hour in late September or in October; most Southern Hemisphere countries that observe daylight saving time set clocks ahead in October or November and reset them in March or April. Equatorial countries do not observe daylight saving time because daylight hours stay about the same from season to season in the lower latitudes. The practice was first suggested in a whimsical essay by Benjamin Franklin in 1784. In 1907 an Englishman,William Willett, campaigned for setting the clock ahead by 80 minutes in four moves of 20 minutes each during the spring and summer months. In 1908 the British House of Commons rejected a bill to advance the clock by one hour in the spring and return Greenwich Mean (standard) Time in the autumn. Several countries, including Australia, Great Britain,Germany, and the United States, adopted summer daylight saving time during World War I to conserve fuel by reducing the need for artificial light. During World War II, clocks were kept continuously advanced by an hour in some nations—for instance, in the US from 9 Feb 1942 to 30 Sep 1945—and England used “double summer time” during part of the year, advancing clocks two hours from the standard time during the summer and one hour during the winter months. In 2005 the US Congress changed the law governing daylight saving time, moving the start of daylight saving time from the first Sunday in April to the second Sunday in March, while moving the end date from the last Sunday in October to the first Sunday in November starting in 2007. In most of the countries of Western Europe, daylight saving time starts on the last Sunday in March and ends on the last Sunday in October.