DAYLIGHT SAVING TIME

also called Summer Time, 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. 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 House of Commons rejected a bill to advance the clock by one hour in the spring and return to 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 nationse.g., in the United States from Feb. 9, 1942, to Sept. 30, 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 the United States, daylight saving time formerly began on the last Sunday in April and ended on the last Sunday in October. In 1986 the U.S. Congress passed a law moving up the start of daylight saving time to the first Sunday in April, while keeping its end date the same. 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 September. In Britain and many other countries worldwide, it lasts from March 30 to October 26.