Why Do We Have Daylight Saving Time?
During summer, most people in the United States set their clocks one hour ahead of standard time. Daylight-saving time doesn’t add any more hours to a day. By setting the clock ahead, it doesn’t get dark until an hour later. As a result, an hour of daylight has been “saved,” giving people extra daylight after work for recreation.
Daylight-saving time begins on the last Sunday in April and ends on the last Sunday in October. We do not have daylight-saving time during the winter, because there is less daylight time then, and not as much daylight can be saved.
New Zealander George Hudson proposed the idea of daylight saving in 1895. The German Empire and Austria-Hungary organized the first nationwide implementation, starting on April 30, 1916. Many countries have used it at various times since then, particularly since the energy crisis of the 1970s.
The practice has both advocates and critics. Putting clocks forward benefits retailing, sports, and other activities that exploit sunlight after working hours, but can cause problems for outdoor entertainment and other activities tied to sunlight, such as farming.
Though some early proponents of DST aimed to reduce evening use of incandescent lighting—once a primary use of electricity —today’s heating and cooling usage patterns differ greatly, and research about how DST affects energy use is limited or contradictory.
DST clock shifts sometimes complicate timekeeping, and can disrupt travel, billing, record keeping, medical devices, heavy equipment, and sleep patterns. Computer software often adjusts clocks automatically, but policy changes by various jurisdictions of DST dates and timings may be confusing.