The main purpose of Daylight Saving Time (called “Summer Time” in many places in the world) is to make better use of daylight.
We change our clocks during the summer months to move an hour of daylight from the morning to the evening. Countries have different change dates.
The idea of daylight saving was first conceived by Benjamin Franklin during a trip to Paris in 1784, in an essay, “An Economical Project.” Looking out the window, Franklin saw the sun rising above the horizon, its rays pouring through the open shutters.
“I looked at my watch, which goes very well, and found that it was but six o clock; and still thinking it something extraordinary that the sun should rise so early, I looked into the almanac, where I found it to be the hour given for his rising on that day. I looked forward too, and found he was to rise still earlier every day towards the end of June; and that no time during the year he retarded his rising so long as till eight o clock. Your readers, who with me have never seen any sign of sunshine before noon, and seldom regard the astronomical part of the almanac, will be as much astonished as I was, when they hear of his rising so early; and especially when I assure them, that he gives light as soon as he rises. I am convinced of this.
It was shortly after this he began to create a plan to encourage others.
To answer skeptics who cried that old habits are hard to change, and it would be difficult to induce the population of Paris to rise before noon, Franklin proposed the following regulations:
- A tax be laid on every window built with shutters to keep out the light of the sun.
- Candles rationed to one pound per family per week, and the regulation enforced by the constabulary.
- Guards posted to stop the passage of all coaches, etc. upon the streets after sunset except those of physicians, surgeons and midwives.
- Every morning as soon as the sun shall rise, church bells and, if necessary, cannon shall inform the citizenry of the advent of light and “awaken the sluggards effectually and make them open their eyes to see their true interests … All the difficulty will be in the first two or three days; after which the reformation will be as natural and easy as the present irregularity. … Oblige a man to rise at four in the morning, and it is probable he will go willingly to bed at eight in the evening.”
A poll conducted by the U.S. Department of Transportation indicated that Americans liked Daylight Saving Time because “there is more light in the evenings / can do more in the evenings.” A 1976 survey of 2.7 million citizens in New South Wales, Australia, found 68% liked daylight saving. Indeed, some say that the primary reason that Daylight Saving Time is a part of many societies is simply because people like to enjoy long summer evenings, and that reasons such as energy conservation are merely rationalizations. 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. Similarly, in New Zealand, power companies have found that power usage decreases 3.5 percent when daylight saving starts. In the first week, peak evening consumption commonly drops around five percent.
For most Americans, daylight saving time 2011 starts at 2 a.m. on Sunday, March 13, when most states spring forward an hour. Time will fall back to standard time again on Sunday, November 6, 2011, when daylight saving time ends. The federal government doesn’t require U.S. states or territories to observe daylight saving time, which is why residents of Arizona, Hawaii, Puerto Rico, the Virgin Islands, American Samoa, Guam, and the Northern Marianas Islands won’t need to change their clocks.