In the European Union , Summer Time begins and ends at a. Universal Time Greenwich Mean Time. It begins the last Sunday in March and ends the last Sunday in October. In the EU, all time zones change at the same moment. During DST, clocks are turned forward an hour, effectively moving an hour of daylight from the morning to the evening. Saving is used here as a verbal adjective a participle. It modifies time and tells us more about its nature; namely, that it is characterized by the activity of saving daylight.
It is a saving daylight kind of time. Because of this, it would be more accurate to refer to DST as daylight-saving time. Similar examples would be a mind-expanding book or a man-eating tiger.
Saving is used in the same way as saving a ball game, rather than as a savings account. Nevertheless, many people feel the word savings with an 's' flows more mellifluously off the tongue. The current schedule was introduced in and follows the Energy Policy Act of The law does not affect the rights of the states and territories that choose not to observe DST.
Historically, there were no uniform rules for DST from to This caused widespread confusion, especially in transport and broadcasting. Following the oil embargo, the US Congress extended the DST period to 10 months in and 8 months in , in an effort to save energy. From to , the country observed DST for about 7 months each year. It's a myth that DST was instituted to help farmers. And so daylight saving time was abolished until the next war brought it back into vogue.
Related: 5 crazy chapters in the history of daylight saving time. After the war, a free-for-all system in which U. That federal law meant that any state observing DST — and they didn't have to jump on the DST bandwagon — had to follow a uniform protocol throughout the state in which daylight saving time would begin on the first Sunday of April and end on the last Sunday of October.
Then, in , the Energy Policy Act of went into effect, expanding the length of daylight saving time to the present timing. However, those who do observe DST take advantage of the natural daylight in the summer evenings. That's because the days start to get longer as Earth moves from the winter season to spring and summer, with the longest day of the year on the summer solstice. During the summer season in each hemisphere, Earth, which revolves around its axis at an angle, is tilted directly toward the sun.
Related: Read more about the science of summer. Regions farthest away from the equator and closer to the poles get the most benefit from the DST clock change, because there is a more dramatic change in sunlight throughout the seasons. Research has also suggested that with more daylight in the evenings, there are fewer traffic accidents, as there are fewer cars on the road when it's dark outside. More daylight also could mean more outdoor exercise or exercise at all for full-time workers.
The nominal reason for daylight saving time has long been to save energy. The time change was first instituted in the U. During the Arab oil embargo, when Arab members of the Organization of Petroleum Exporting Countries OPEC stopped selling petroleum to the United States, Congress even enacted a trial period of year-round daylight saving time in an attempt to save energy. But the evidence for energy savings is slim. Brighter evenings may save on electric lighting, said Stanton Hadley, a senior researcher at Oak Ridge National Laboratory who helped prepare a report to Congress on extended daylight saving time in But lights have become increasingly efficient, Hadley said, so lighting is responsible for a smaller chunk of total energy consumption than it was a few decades ago.
Heating and cooling probably matter more, and some places may need air-conditioning for the longer, hotter evenings of summer daylight saving time. Hadley and his colleagues found that the four weeks of extra daylight saving time that went into effect in the United States in did save some energy, about half of a percent of what would have otherwise been used on each of those days. However, Hadley said, the effect of the entire months-long stretch of daylight saving could very well have the opposite effect.
A study in Indiana before and after implementation of daylight saving time in some counties found a small increase in residential energy usage. Temporary changes in Australia's daylight saving timing for the summer Olympics of also failed to save any energy, a study found. Part of the trouble with estimating the effect of daylight saving time on energy consumption is that there are so few changes to the policy, making before-and-after comparisons tricky, Hadley told Live Science.
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