I love sunflowers and thought it was a good excuse to use one in this account of Daylight Saving Time (or Daylight Savings Time, as many people say) from www.webexhibits.org
Just as sunflowers turn their heads to catch every sunbeam, so too have we discovered a simple way to get more from our sun.
Daylight Saving Time begins at 2 a.m. Sunday, March 8, 2009, so set your clocks ahead one hour before going to bed Saturday night.
I, for one, am looking forward to the time change and wish it were year-round. I know there have been studies that show people have trouble adjusting their sleep schedules during the fall and spring time changes. In the last two years, we have extended the length of Daylight Saving Time in the U.S. – a positive move, in my opinion. Anyone else like to weigh in?
Whether you agree or disagree, you might find the history behind Daylight Saving Time interesting. Following are some tidbits from the WebExhibits site. Much more can be found at: http://www.webexhibits.org/daylightsaving/index.html
According to some sources, DST saves energy. Studies done by the U.S. Department of Transportation in 1975 showed that Daylight Saving Time trims the entire country’s electricity usage by a small but significant amount, about one percent each day, because less electricity is used for lighting and appliances.
The rationale behind the 1975 study of DST-related energy savings was that energy use and the demand for electricity for lighting homes is directly related to the times when people go to bed at night and rise in the morning. In the average home, 25 percent of electricity was used for lighting and small appliances, such as TVs and stereos. A good percentage of energy consumed by lighting and appliances occurred in the evening when families were home. By moving the clock ahead one hour, the amount of electricity consumed each day decreased.
In the summer, people who rose before the sun rises used more energy in the morning than if DST were not in effect. However, although 70 percent of Americans rose before 7 a.m., this waste of energy from having less sunlight in the morning was more than offset by the savings of energy that results from more sunlight in the evening.
In the winter, the afternoon Daylight Saving Time advantage is offset for many people and businesses by the morning’s need for more lighting. In spring and fall, the advantage is generally less than one hour. So, the rationale was that Daylight Saving Time saves energy for lighting in all seasons of the year, but it saves least during the four darkest months of winter (November, December, January, and February), when the afternoon advantage is offset by the need for lighting because of late sunrise.
In addition, less electricity was thought to be used because people are home fewer hours during the “longer” days of spring and summer. Most people plan outdoor activities in the extra daylight hours. When people are not at home, they don’t turn on the appliances and lights. Although a 1976 report by the National Bureau of Standards disputed the 1975 U.S. Department of Transportation study, and found that DST-related energy savings were insignificant, the DOT study continued to influence decisions about Daylight Saving Time.
The argument in favor of saving energy swayed Indiana, where until 2005, only about 16 percent of counties observed Daylight Saving Time. Based on the DOT study, advocates of Indiana DST estimated that the state’s residents would save over $7 million in electricity costs each year. Now that Indiana has made the switch, however, researchers have found the opposite to be the case. Scientists from the University of California, Santa Barbara, compared energy usage over the course of three years in Indiana counties that switched from year-round Standard Time to DST. They found that Indianans actually spent $8.6 million more each year because of Daylight Saving Time, and increased emissions came with a social cost of between $1.6 million and $5.3 million per year. Commentators have theorized that the energy jump is due to the increased prevalence of home air conditioning over the past 40 years, in that more daylight toward the end of a summer’s day means that people are more likely to use their air conditioners when they come home from work.
However, the Indiana research findings don’t necessarily apply elsewhere. In cooler climates, for example, energy savings may well occur. In addition, some argue that there is a public health benefit to Daylight Saving Time, as it decreases traffic accidents. Several studies in the U.S. and Great Britain have found that the DST daylight shift reduces net traffic accidents and fatalities by close to one percent. An increase in accidents in the dark mornings is more than offset by the evening decrease in accidents.
However, recent research indicates that pedestrian fatalities from cars soar at 6:00 p.m. during the weeks after clocks are set back in the fall. Walkers are three times as likely to be hit and killed by cars right after the switch than in the month before DST ends. Researchers from Carnegie Mellon University, who found a 186 percent jump in the risk of being killed by a car for every mile walked, speculate that drivers go through an adjustment period when dusk arrives earlier. Although the risk drops in the morning, because there are fewer pedestrians at 6:00 a.m., the lives saved in the morning don’t offset those lost in the evening. This research corroborates a 2001 study by researchers at the University of Michigan, which found that 65 pedestrians were killed by car crashes in the week before DST ended, and 227 pedestrians were killed in the week following the end of DST.
There may also be an economic benefit to DST, as daylight evening hours encourage people to go out and shop, potentially spurring economic growth.
The Daylight Saving Time plan was not formally adopted in the U.S. until 1918. ‘An Act to preserve daylight and provide standard time for the United States‘ was enacted on March 19, 1918. See law
Under legislation enacted in 1986, Daylight Saving Time in the U.S. began at 2 a.m. on the first Sunday of April and ended at 2 a.m. on the last Sunday of October.
The Energy Policy Act of 2005 extended Daylight Saving Time in the U.S. beginning in 2007, though Congress retained the right to revert to the 1986 law should the change prove unpopular or if energy savings are not significant. Going from 2007 forward, Daylight Saving Time in the U.S.
- begins at 2 a.m. on the second Sunday of March and
- ends at 2 a.m. on the first Sunday of November