Daylight saving time

Daylight Saving Time (DST) is the practice of setting the clock ahead by one hour from Standard Time during the warmer part of the year, so that evenings have more daylight and mornings have less. Most areas of the United States and Canada observe daylight saving time, the exceptions being Arizona (except for the Navajo Nation, which does observe daylight saving time), Hawaii, and the overseas territories of American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the United States Virgin Islands.

History

The idea of daylight saving was first conceived by Benjamin Franklin during his sojourn as an American delegate in Paris in 1784, in an essay, "An Economical Project." More than a century later, George Vernon Hudson, an entomologist from New Zealand, proposed a two-hour daylight saving shift. However, the modern concept of DST was proposed in 1907 by the English builder and outdoorsman William Willett.

Implementation

The implementation of DST has been fraught with controversy since it began. The Uniform Time Act of 1966 provided the basic framework for alternating between DST and standard time, which we now observe in the United States. But Congress can’t seem to resist tinkering with it. For example, in 1973 daylight saving time was observed all year, instead of just the spring and summer.

Effects

The impact of DST has been the subject of much debate. It has been argued that DST saves energy, promotes outdoor leisure activity in the evening (in summer), and is therefore good for physical and psychological health, reduces traffic accidents, reduces crime, or is good for business. Others argue that actual energy savings are inconclusive, that DST increases health risks such as heart attack, that it can disrupt morning activities, and that the act of changing clocks twice a year is economically and socially disruptive and cancels out any benefit.

See also

• Standard time
• Time zone
• Winter time (clock lag)

• Map of countries using daylight saving time
  Map of countries using daylight saving time
• Diagram of a clepsydra
  Diagram of a clepsydra
• George Vernon Hudson
  George Vernon Hudson
• "Saving Daylight" poster
  "Saving Daylight" poster
• Victory cigar for Congress passing DST
  Victory cigar for Congress passing DST
• William Willett
  William Willett
• Daylight saving time illustration
  Daylight saving time illustration
• Willett memorial
  Willett memorial