Daylight saving time (also called DST, or summer time) is the portion of the year in which a region's local time is advanced by (usually) one hour from its official standard time. It is most common in temperate regions. In electronics, a summer is a circuit or system that adds one or more input voltages or currents together (usually by means of operational amplifiers), giving an output equal to the algebraic sum of the inputs. ... In geography, temperate latitudes of the globe lie between the tropics and the polar circles. ...

"Daylight saving time" is a system intended to "save" daylight, as opposed to "wasting" time (for example, by sleeping long past sunup). The official time is adjusted forward during the spring and summer months, so that the active hours of work and school will better match the hours of daylight. A girl sleeping Sleep is the regular state of natural unconsciousness observed in all mammals and birds. ...

The list of time zones has information on which areas do or do not observe DST. Time zones are areas of the Earth that have adopted the same standard time, usually referred to as the local time. ...

The expression daylight savings time (with the extra "s") is a common alternate form but is sometimes considered to be improper English because "saving" is used here as a verbal adjective describing a single type of activity. Because "daylight saving" is a compound adjective, the proper form would actually be daylight-saving time, with the hyphen. In linguistics, a participle is an adjective derived from a verb. ... A compound is a word composed of more than one free morphemes. ... A hyphen ( - ) is a punctuation mark. ...

Origin

It is sometimes asserted that DST was first proposed by Benjamin Franklin in a letter to the editors of the Journal of Paris [1]. However, the article was humorous; Franklin was not proposing DST, but rather that people should get up and go to bed earlier. Benjamin Franklin by Jean-Baptiste Greuze 1777 For the former mayor of Nepean, see Ben Franklin (politician) Dr. Benjamin Franklin (January 17, 1706 – April 17, 1790) was an American printer, journalist, publisher, author, philanthropist, abolitionist, public servant, scientist, librarian, diplomat,Atheist and inventor. ...

It was first seriously proposed by William Willett in the "Waste of Daylight" [2], published in 1907, but he was unable to get the British government to adopt it, despite considerable lobbying. William Willett (August 10, 1856 - March 4, 1915) is the inventor of Daylight saving time. ... 1907 was a common year starting on Tuesday (see link for calendar). ... The Parliament of the United Kingdom of Great Britain and Northern Ireland is the supreme legislative institution in the United Kingdom and British overseas territories (it alone has parliamentary sovereignty). ... Lobbying is the practice of private advocacy with the goal of influencing a governing body, in order to ensure that an individuals or organizations point of view is represented in the government. ...

The idea of daylight saving time was first put into practice by the German government during the First World War between April 30 and October 1, 1916. Shortly afterward, the United Kingdom followed suit, first adopting DST between May 21 and October 1, 1916. Then on March 19, 1918, the U.S. Congress established several time zones (which were already in use by railroads and most cities since 1883) and made daylight saving time official (which went into effect on March 31) for the remainder of World War I. It was observed for seven months in 1918 and 1919. The law, however, proved so unpopular (mostly because people rose and went to bed earlier than in modern times) that the law was later repealed. World War I was primarily a European conflict with many facets: immense human sacrifice, stalemate trench warfare, and the use of new, devastating weapons - tanks, aircraft, machineguns, and poison gas. ... April 30 is the 120th day of the year in the Gregorian calendar (121st in leap years), with 245 days remaining, as the last day in April. ... October 1 is the 274th day of the year (275th in Leap years). ... 1916 - Wikipedia, the free encyclopedia /**/ @import /skins-1. ... May 21 is the 141st day of the year in the Gregorian calendar (142nd in leap years). ... October 1 is the 274th day of the year (275th in Leap years). ... 1916 - Wikipedia, the free encyclopedia /**/ @import /skins-1. ... March 19 is the 78th day of the year in the Gregorian calendar (79th in leap years). ... 1918 was a common year starting on Tuesday (see link for calendar). ... Seal of the Congress. ... Time zones are areas of the Earth that have adopted the same standard time, usually referred to as the local time. ... This is the top-level page of WikiProject trains Rail tracks Rail transport refers to the land transport of passengers and goods along railways or railroads. ... 1883 was a common year starting on Monday (see link for calendar). ... March 31 is the 90th day of the year in the Gregorian Calendar (91st in Leap years), with 275 days remaining, as the final day of March. ... 1918 was a common year starting on Tuesday (see link for calendar). ... 1919 was a common year starting on Wednesday (see link for calendar). ... A repeal is the removal or reversal of a law. ...

Observation of DST

Daylight saving time is generally a temperate zone practice; day lengths in the tropics do not vary enough to justify DST. Hawaii, the only U.S. state in the tropics, does not observe DST. However, Mexico has adopted DST nationwide, even in its tropical regions, because of its increasing economic ties to the United States. The Mexican state of Sonora does not observe DST because it borders on the U.S. state of Arizona which also does not observe DST (except in the large Navajo Indian Reservation in northeastern Arizona). Polar or near-polar locations such as Iceland often opt out as well, as summer in these locations usually brings nearly uninterrupted daylight. In geography, temperate latitudes of the globe lie between the tropics and the polar circles. ... The tropics are the geographic region of the Earth centered on the equator and limited in latitude by the two tropics: the Tropic of Cancer in the north and the Tropic of Capricorn in the southern hemisphere. ... State nickname: The Aloha State Other U.S. States Capital Honolulu Largest city Honolulu Governor Linda Lingle (R) Official languages Hawaiian and English Area 28,337 km² (43rd)  - Land 16,649 km²  - Water 11,672 km² (41. ... This article is about the Mexican state of Sonora. ... State nickname: The Grand Canyon State, The Copper State Other U.S. States Capital Phoenix Largest city Phoenix Governor Janet Napolitano (D) Official languages English Only State Area 295,254 km² (6th)  - Land 294,312 km²  - Water 942 km² (0. ... Manuelito, Navajo chief Navajo Nation (Navajo Naabeehó Dineé) is the name of a sovereign Native American nation established by the Diné. The Navajo Nation Reservation includes about 27,000 square miles (70,000 km²) of land, slightly smaller than Maine or South Carolina) over part of three states, and is...

The amount of the time shift varies, but one hour is the most common. The dates of the beginning and ending of DST also vary by country. With a few exceptions, switchovers between standard time and daylight saving time generally occur in the early morning hours of a Sunday morning, presumably because doing so then causes less disruption than a change on a weekday would.

DST commonly begins in the Northern Hemisphere on either the first Sunday in April or the last Sunday in March, and ends on the last Sunday in October. In the Southern Hemisphere, the beginning and ending dates are switched (thus the time difference between, e.g., the United Kingdom and Chile may be three, four, or five hours). The Northern Hemisphere is the half of a planets surface (or celestial sphere) that is north of the equator. ... The Southern Hemisphere is the half of a planets surface (or celestial sphere) that is south of the equator (the word hemisphere literally means half ball). On Earth it contains four continents (part of Africa, Australia, most of South America, and Antarctica) and four oceans (South Atlantic, Indian, Pacific...

North America generally follows the same procedure, going by local time in each zone, each time zone switching at 02:00 LST (local standard time) to 03:00 LDT (local daylight time) on the first Sunday in April, and again from 02:00 LDT to 01:00 LST on the last Sunday in October. The Canadian province of Newfoundland and Labrador is an exception in that the time changes take place at 00:01 local standard time and 00:01 local daylight time respectively. Also, in 1990, they experimented with Double Daylight Time, when the clocks went ahead by two hours, instead of the usual one hour. The Energy Policy Act of 2005, signed by President George W. Bush will extend DST, which might prompt neighboring countries with integrated economies and schedules (especially Canada and Mexico) to adopt these changes as well. World map showing location of North America A satellite composite image of North America North America is a continent in the northern hemisphere, bounded on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the south by the Caribbean Sea, and on the west... Motto: Quaerite Primum Regnum Dei (Seek ye first the kingdom of God) Other Canadian provinces and territories Capital St. ... 1990 is a common year starting on Monday of the Gregorian calendar. ... The Energy Policy Act of 2005 (official short title) is a bill passed by the United States Congress. ... George Walker Bush (born July 6, 1946) is the 43rd and current President of the United States. ...

All countries in Europe, except Iceland as already noted, observe daylight-saving time and change on the same date: moving clocks forward one hour on the last Sunday in March and back one hour on the last Sunday in October. In the West European (UTC), Central European (UTC+1), and East European (UTC+2) time zones the change is simultaneous: on both dates the clocks are changed everywhere at 01:00 UTC, i.e. from local times of 01:00/02:00/03:00 to 02:00/03:00/04:00 in March, and vice versa in October. (See also: European Summer Time). In Russia, however, although the changeover dates are the same, clocks are moved forward or back at 02:00 local time in all zones. Thus in Moscow (local time = UTC+3 in winter, UTC+4 in summer), daylight-saving time commences at 05:00 UTC on the last Sunday in March, and ends at 06:00 UTC on the last Sunday in October. World map showing location of Europe Europe is geologically and geographically a peninsula, forming the westernmost part of Eurasia. ... UTC also stands for the University of Tennessee at Chattanooga Coordinated Universal Time or UTC, also sometimes referred to as Zulu time, the basis for civil time, differs by an integral number of seconds from atomic time and a fractional number of seconds from UT1. ... European Summer Time is the daylight saving time practised in Europe, the period during which clocks are advanced by one hour in relation to the official time observed during the rest of the year. ...

With Iceland observing UTC all year round, despite being at a longitude which would indicate UTC-1, the country may be said to be on continuous DST.

Egypt switches to DST on midnight of the last Thursday of April, since the weekend holiday for most Egyptians is on Friday, thus giving workers and students a chance to adjust. Israel adopts Daylight Saving Time on the last Friday of March at 02:00, and returns to standard time at 02:00 of the Sunday of the month of Tishrei between Rosh Hashanah and Yom Kippur. Tishrei or Tishri (תִּשְׁרִי, תִּשְׁרֵי, Standard Hebrew Tišri, Tišre, Tiberian Hebrew Tišrî, Tišrê: from Akkadian tašrītu Beginning, from šurrû To begin) is the first month of the ecclesiastical year and the seventh month of the civil year on the Hebrew calendar. ... This article is about the Jewish holiday of Rosh Hashanah. ... Yom Kippur (1878) Yom Kippur (יום כפור yome kippÅ«r, day of atonement) is the Jewish holiday of the Day of Atonement. ...

The People's Republic of China experimented with DST from 1986, but abandoned it in the 1990s. The PRC now uses one universal time zone for all of the nation from Urumqi in the northwest to Fujian in the southeast; the size of the nation was a major factor why DST was not considered practical in China. 1986 is a common year starting on Wednesday of the Gregorian calendar. ... // Events and trends The 1990s are generally classified as having moved slightly away from the more conservative 1980s, but otherwise retaining the same mindset. ... Ürümqi (Uyghur: ئۈرۈمچى; Uyghur Latin script: Ürümqi; Chinese: 烏魯木齊; Pinyin: Wūlǔmùqí; population about 1. ... Fujian (Chinese: 福建; pinyin: ; Wade-Giles: Fu-chien; Postal System Pinyin: Fukien, Foukien; local transliteration Hokkien from Min Nan Hok-kiàn) is one of the provinces on the southeast coast of China. ...

Australia has a mixed implementation of daylight saving time. During winter it has three time zones, but when daylight saving time is in effect, it has five time zones (mostly differing by 30 minutes) ranging from UTC+8 to UTC+11. Although there have been several referenda on the topic, Western Australia, the Northern Territory and Queensland have not adopted the practice. As a result, the tropical regions of the country do not observe daylight saving. Interestingly, during daylight saving time, South Australia observes a time later than Queensland, despite the latter being almost entirely further east. Tasmania starts DST earlier than the rest of the country, usually at the start of October. A referendum (plural: referendums or referenda) or plebiscite is a direct vote in which an entire electorate is asked to either accept or reject a particular proposal. ... Motto: Cygnis Insignis (Distinguished by its swans) Nickname: Wildflower State Other Australian states and territories Capital Perth Government Governor Premier Const. ... Motto: None Nickname: ? Other Australian states and territories Capital Darwin Government Administrator Chief Minister Const. ... Motto: Audax at Fidelis (Bold but Faithful) Nickname: Sunshine State/Smart State Other Australian states and territories Capital Brisbane Government Governor Premier Const. ... Motto: United for the Common Wealth Nickname: Festival State Other Australian states and territories Capital Adelaide Government Governor Premier Const. ... Motto: Ubertas et Fidelitas (Fertility and Faithfulness) Nickname: The Apple Isle Other Australian states and territories Capital Hobart Government Governor Premier Const. ...

Cuba always starts its DST on April 1 but the end date varies.

Brazil adopted DST for the first time in 1931, but uninterruptedly since 1985 in southern states (south, southeast regions and states of Goiás and Mato Grosso do Sul). Starting and ending dates are variable: normally, Brazilian DST starts at 00:00 on an October (rarely November) Sunday and ends at 00:00 on a February Sunday. 1931 is a common year starting on Thursday. ... 1985 is a common year starting on Tuesday of the Gregorian calendar. ... Goiás is a state of Brazil, located in the central part of the country. ... Mato Grosso do Sul is one of the states of Brazil, located in the western part of the country. ...

The Canadian province of Saskatchewan is the only part of that country (other than northeastern British Columbia and Southampton Island) that does not use DST. However, the charter of the city of Lloydminster, which is bisected by the Saskatchewan–Alberta border, gives it the special exception of using DST. Lloydminster and its immediately surrounding region in Saskatchewan use DST with Mountain Standard Time, which is the time used by Alberta. Motto: Multis E Gentibus Vires (From many peoples, strength) Other Canadian provinces and territories Capital Regina Largest city Saskatoon Lieutenant Governor Lynda M. Haverstock Premier Lorne Calvert (NDP) Area 651,036 km² (7th)  - Land 591,670 km²  - Water 59,366 km² (9. ... Motto: Splendor Sine Occasu (Splendour without diminishment) Other Canadian provinces and territories Capital Victoria Largest city Vancouver Lieutenant Governor Iona Campagnolo Premier Gordon Campbell (BC Liberal) Area 944,735 km² (5th)  - Land 925,186 km²  - Water 19,549 km² (2. ... Categories: Islands of Canada | Canada geography stubs ... Lloydminster is a Canadian city which has the unusual geographic distinction of straddling a provincial border. ... Motto: Fortis et Liber (Strong and free) Other Canadian provinces and territories Capital Edmonton Largest city Calgary Lieutenant Governor Norman Kwong Premier Ralph Klein (PC) Area 661,848 km² (6th)  - Land 642,317 km²  - Water 19,531 km² (2. ... MST is UTC-7 The Mountain Standard Time Zone (MST) is a geographic region that keeps time by subtracting seven hours from Coordinated Universal Time (UTC), resulting in UTC-7. ...

In the US

Daylight saving time was reinstated in the United States on February 9, 1942, again as a wartime measure to conserve resources. This remained in effect until World War II began winding down and the requirement was removed on September 30, 1945. February 9 is the 40th day of the year in the Gregorian Calendar. ... This article is about the year. ... World War II was a truly global conflict with many facets: immense human suffering, fierce indoctrinations, and the use of new, extremely devastating weapons like the atom bomb. ... September 30 is the 273rd day of the year (274th in leap years) in the Gregorian Calendar, with 92 days remaining, as the final day of September. ... 1945 was a common year starting on Monday (link will take you to calendar). ...

From 1945 to 1966, U.S. federal law did not address daylight saving time. States and localities were free to observe daylight saving time or not. This resulted in a patchwork where some areas observed DST while adjacent areas did not, and it was not unheard of to have to reset one's clock several times during a relatively short trip (e.g., bus drivers operating between Moundsville, West Virginia, and Steubenville, Ohio had to reset their watches seven times over 35 miles). 1945 was a common year starting on Monday (link will take you to calendar). ... 1966 was a common year starting on Saturday (link goes to calendar) // Events January January 1 - In a coup, Colonel Jean-Bédel Bokassa ousts president David Dacko and takes over the Central African Republic. ... Moundsville is a city located in Marshall County, West Virginia. ... Steubenville is a city located in Jefferson County, Ohio. ...

The U.S. federal Uniform Time Act of 1966 mandated that daylight saving time begin nationwide on the last Sunday of April and end on the last Sunday of October. Any state that wanted to be exempt from daylight saving time could do so by passing a state law, provided that it exempt the entire state. The law was amended in 1972 to permit states that straddle a time zone boundary to exempt the entire area of the state lying in one time zone. The law was amended again in 1986 to begin daylight saving time on the first Sunday in April, to take effect the following year. In the United States, the Uniform Time Act is a federal law, enacted in 1966, whose effect was to simplify the official pattern of where and when Daylight saving time (DST) is applied within the U.S. Previous to this law, each state worked out its own scheme for the... April is the fourth month of the year in the Gregorian Calendar and one of four with the length of 30 days. ... October is the tenth month of the year in the Gregorian Calendar and one of seven Gregorian months with the length of 31 days. ... 1972 was a leap year that started on a Saturday. ... 1986 is a common year starting on Wednesday of the Gregorian calendar. ... Sunday is considered either the first or the seventh day of the week, between Saturday and Monday, and the second day of the weekend in some cultures. ... April is the fourth month of the year in the Gregorian Calendar and one of four with the length of 30 days. ...

In response to the 1973 energy crisis, daylight saving in the United States was begun earlier in both 1974 and 1975, commencing on the first Sunday in January in the former year and the last Sunday in February in the latter. (Redirected from 1973 energy crisis) United States, drivers of vehicles with odd numbered license plates were allowed to purchase gasoline only on odd-numbered days of the month, while drivers with even-numbers were limited to even-numbered days. ... 1974 is a common year starting on Tuesday (click on link for calendar). ... 1975 was a common year starting on Wednesday (the link is to a full 1975 calendar). ... Sunday is considered either the first or the seventh day of the week, between Saturday and Monday, and the second day of the weekend in some cultures. ... January is the first month of the year in the Gregorian Calendar and one of seven Gregorian months with the length of 31 days. ... Sunday is considered either the first or the seventh day of the week, between Saturday and Monday, and the second day of the weekend in some cultures. ... February is the second month of the year in the Gregorian Calendar. ...

Starting March 11, 2007, daylight saving time will be extended another four to five weeks, from the second Sunday of March to the first Sunday of November. The change was introduced by the Energy Policy Act of 2005; the House had originally approved a motion that would have extended DST even further. Proponents claimed that the extension would save "the equivalent of" 10,000 barrels of oil per day, but this figure was based on U.S. Department of Energy information from the 1970s, the accuracy and relevance of which the DoE no longer stands by. There is very little recent research on what the actual positive effects, if any, might be. [3] [4] 11 March is the 70th day of the year in the Gregorian Calendar (71st in Leap year). ... 2007 is a common year starting on Monday of the Gregorian calendar. ... The Energy Policy Act of 2005 (official short title) is a bill passed by the United States Congress. ... The House of Representatives is the larger of two houses that make up the U.S. Congress, the other being the United States Senate. ... See Barrel for other uses. ... Oil is a generic term for organic liquids that are not miscible with water. ... The United States Department of Energy (DOE) is a Cabinet-level department of the United States government responsible for energy policy and nuclear safety. ... This article provides extensive lists of events and significant personalities of the 1970s. ...

The extension, which puts the U.S. out of step with every other country in the world (including Canada), was greeted by criticism from the airline industry [5], observant Jews [6], and those concerned for the safety of children traveling to school in the dark before the late sunrise [7]. Many businesses will have to reprogram or replace devices such as time clocks, security systems, and timed safes; traffic lights must be adjusted to properly recognize rush hour. Devices that use atomic time from radio clocks will adjust automatically, but such devices are rare, and it is difficult to receive the signals inside buildings. Many devices, such as VCRs, cannot be updated at all and will need to be manually adjusted twice a year. Sunrise over the sea Sunrise, also called sunup in some American English dialects, is the time at which the first part of the Sun appears above the horizon in the east. ... A time clock is an informal general name for a form of clock that is designed to measure the amount of time an employee of a business is entitled to be paid. ... 1 example. ... Traffic lights can have several additional lights for filter turns or bus lanes. ... Rush hour in a city A rush hour is a part of the day with busy traffic and hence traffic congestion on the roads and crowded public transport; normally the two periods in a day when people are travelling to or from work or school. ... Temps Atomique International (TAI) or International Atomic Time is a very accurate and stable time scale. ... A radio clock A radio clock is a clock that is synchronized by a time code transmitted by a radio transmitter connected to a time standard such as an atomic clock. ... Building is either the act of creating an object assembled from more than one element, or the object itself; see also construction. ... The video cassette recorder (or VCR, less popularly video tape recorder) is a type of video tape recorder that uses removable cassettes containing magnetic tape to record audio and video from a television broadcast so it can be played back later. ...

DST and the state of Indiana

DST is a long-standing controversy in Indiana, not only as an agricultural state, but also because the border separating the eastern and central time zones divides the state. In the past, neighboring communities sometimes ended up one or even two hours apart. Being out-of-sync with neighboring states and the national changing of clocks, it is argued, has a negative economic impact on the state. It has been demonstrated that some businesses have located outside of the state once the confusion related to not changing clocks is discovered. In the current compromise, the state has three kinds of time zones: State nickname: The Hoosier State Other U.S. States Capital Indianapolis Largest city Indianapolis Governor Mitch Daniels (R) Official languages English Area 94,321 km² (38th)  - Land 92,897 km²  - Water 1,424 km² (1. ... Time zones are areas of the Earth that have adopted the same standard time, usually referred to as the local time. ...

• 77 counties, most of the state, are on Eastern Standard Time but do not use DST;
• 5 counties near Chicago, Illinois and 5 counties in the southwestern corner of the state are on Central Standard Time and do use DST; and
• 2 counties near Cincinnati, Ohio and 3 counties near Louisville, Kentucky are on Eastern Standard time but do observe DST. Their observance of DST is unofficial in this case, as a strict reading of the Uniform Time Act would not allow for this situation, but by observing DST, they remain synchronized with the greater Louisville and Cincinnati metropolitan areas.

On April 29, 2005, the Indiana legislature voted to begin observing daylight-saving time in 2006. Currently, the state is in the Eastern time zone; however, its time zone is currently under federal review[8]. There was further controversy after this passed, as some people that supported it initially had thought that the time would fall back an extra hour in winter instead of going ahead an extra hour in summer. Chicago, colloquially known as the Second City and the Windy City, is the third-largest city in population in the United States and the largest inland city in the country. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Louisville (usually pronounced ; see Pronunciation below) is Kentuckys largest city and the 16th largest city of the United States. ... April 29 is the 119th day of the year in the Gregorian calendar (120th in leap years). ... 2005 is a common year starting on Saturday of the Gregorian calendar and is the current year. ...

Rationales for DST

One of the major reasons given for observing DST in the United States is energy conservation. Theoretically, the amount of residential electricity needed in the evening hours is dependent both on when the sun sets and when people go to bed. Because people tend to observe the same bedtime year-round, by artificially moving sunset one hour later, the amount of energy used is theoretically reduced. United States Department of Transportation studies showed that DST reduces the country's electricity usage by one percent during each day DST is in effect. Established October 15, 1966 Activated April 1, 1967 Secretary Norman Mineta Deputy Secretary Kirk K. Van Tine (acting) Budget $58 billion (2004 estimate) Employees 58,622 (2004 estimate) The United States Department of Transportation (DOT) is a Cabinet department of the United States government concerned with transport. ...

Part of the reason that it is normally observed in the late spring, summer, and early autumn is because during the winter months the amount of energy saved by moving sunset one hour later is negated by the increased need for morning lighting by moving sunrise by the same amount. During the summer most people would wake up after the sun rises, regardless of whether daylight saving time is in effect or not, so there is no increased need for morning lighting to offset the afternoon energy savings.

Another perceived benefit of DST is increased opportunities for outdoor activities. Most people plan outdoor activities during the increased hours of sunlight. Other benefits cited include prevention of traffic injuries (by allowing more people to return home from work or school in daylight), and crime reduction (by reducing people's risk of being targets of crimes that are more common in dark areas).

When the U.S. went on extended DST in 1974 and 1975 in response to the 1973 energy crisis, Department of Transportation studies found that observing DST in March and April saved 10,000 barrels of oil a day, and prevented about 2,000 traffic injuries and 50 fatalities saving about U.S. $28 million in traffic costs. [9] 1974 is a common year starting on Tuesday (click on link for calendar). ... 1975 was a common year starting on Wednesday (the link is to a full 1975 calendar). ... (Redirected from 1973 energy crisis) United States, drivers of vehicles with odd numbered license plates were allowed to purchase gasoline only on odd-numbered days of the month, while drivers with even-numbers were limited to even-numbered days. ... The United States dollar is the official currency of the United States. ...

Criticism of DST

DST is not universally accepted; many localities do not observe it. Opponents claim that there is not enough benefit to justify needing to adjust clocks twice every year. The disruption in sleep patterns associated with setting clocks forward, and thereby "losing" an hour, correlates with a spike in the number of severe auto accidents, as well as emotional trauma and lost productivity as tired workers adjust to the schedule change. It is also noted that much effort is spent reminding everyone twice a year of the change, and thousands are inconvenienced by showing up at the wrong time when they forget.

There is also a question whether the savings in lighting costs justifies the increase in summertime air conditioning costs. While most people use more sunlight under DST, most people also experience more heat, which prompts many people to turn on the air conditioner during the warmer afternoon hours. When air conditioning was not widely available, the change did save energy; however, air conditioning is much more widespread now than it was several decades ago. Air conditioning often uses more energy than artificial lighting. Note: in the broadest sense, air conditioning can refer to any form of heating, ventilation, and air-conditioning. ...

No formal studies have been performed, but an enormous amount of time has been spent by software developers to deal with the fact that 2400 hours past 2pm is not necessarily 2pm 100 days later.

Some campaigners in Britain would like the country to stay on British Summer Time (BST) all year round, or in other words, adopt Central European Time and abolish BST. Alternatively, some would like Britain to adopt Central European Time and jump forward another hour during the summer (adopting a Single/Double Summer Time from Britain's perspective). This would make winter evenings longer, thereby reducing traffic accidents and cases of seasonal affective disorder. Opponents point to the longer hours of darkness on winter mornings, especially in Scotland, which might well cause an increase in road accidents. It has even been suggested that Scotland should be placed on a different time zone from the rest of the UK, which, unlikely though it may sound, would be possible as the UK Parliament could legislate to put the UK forward an hour, and then the Scottish Parliament could put Scotland back onto GMT. British Summer Time (BST), known in Ireland as Irish Summer Time (IST), is the daylight saving time in effect in the United Kingdom and Republic of Ireland between the last Sunday in March and the last Sunday in October each year. ... Central European Time (CET) is one of the names of UTC+1 time zone, 1 hour ahead of Coordinated Universal Time. ... Seasonal affective disorder, or SAD, is an affective, or mood disorder. ... Scotland (Alba in Scottish Gaelic) is a country in northwest Europe and a constituent nation of the United Kingdom. ... Time zones are areas of the Earth that have adopted the same standard time, usually referred to as the local time. ... The Parliament of the United Kingdom of Great Britain and Northern Ireland is the supreme legislative institution in the United Kingdom and British overseas territories (it alone has parliamentary sovereignty). ... The Scottish Parliament (Pàrlamaid na h-Alba in Gaelic, Scots Pairlament in Scots) is the national unicameral legislature of Scotland. ...

DST is particularly unpopular among people working in agriculture because the animals do not observe it, and thus the people are placed out of synchronization with the rest of the community, including school times, broadcast schedules, and the like.

Canadian author Robertson Davies, in The Diary of Samuel Marchbanks (1947), wrote the following: "I object to being told that I am saving daylight when my reason tells me that I am doing nothing of the kind ... At the back of the Daylight Saving scheme, I detect the bony, blue-fingered hand of Puritanism, eager to push people into bed earlier, and get them up earlier, to make them healthy, wealthy, and wise in spite of themselves." Robertson Davies in 1984 Robertson Davies, CC , B.Litt. ... The Diary of Samuel Marchbanks, published in 1947, is the first of the Marchbanks Books by Canadian novelist and journalist Robertson Davies. ... 1947 was a common year starting on Wednesday (link will take you to calendar). ...

Mnemonic

The mnemonic "spring forward, fall back" tells us how to reset clocks when the time changes, regardless of hemisphere (although it has to be remembered that spring and autumn occur during different months in the northern and southern hemispheres). This uses the word "fall" to mean "autumn"; while this usage has died out in British English, it is still very common in American English and Canadian English. A mnemonic (pronounced in American English, in British English) is a memory aid. ... Autumn colours at Westonbirt Arboretum, Gloucestershire, England. ... British English is a term used by people outside the UK to refer to the form of the English language spoken in the British Isles. ... American English is the form of the English language used mostly in the United States of America. ... Canadian English is the form of English used in Canada, spoken as a first or second language by over 25 million Canadians (as recorded in the 2001 census [1]). Canadian English spelling is a mixture of American and British, but Canadian English pronunciation is much closer to that of American...

Associated practices

Fire safety officials in Australia, Canada, New Zealand, and the United States encourage citizens to use the two annual time changes as a reminder to check the batteries in home and office fire alarms and smoke detectors. For example, the Country Fire Authority of Victoria in Australia has been running a program called "Change Your Clock, Change Your Smoke Alarm Battery" for several years. This is especially important in autumn, just before the heating season causes an increase in home fires. Residential ceiling-mounted smoke detector A smoke detector (sometimes called a smoke alarm) is a safety device that detects airborne smoke and issues an audible alarm, thereby alerting nearby people to the danger of fire. ... HVAC may also stand for High-voltage alternating current HVAC is an initialism that stands for heating, ventilation and air-conditioning. This is sometimes referred to as climate control. ... A large bonfire Fire is a form of combustion. ...

See also

• British Summer Time
• European Summer Time

British Summer Time (BST), known in Ireland as Irish Summer Time (IST), is the daylight saving time in effect in the United Kingdom and Republic of Ireland between the last Sunday in March and the last Sunday in October each year. ... European Summer Time is the daylight saving time practised in Europe, the period during which clocks are advanced by one hour in relation to the official time observed during the rest of the year. ...

Books

• Seize the Daylight: The Curious and Contentious Story of Daylight Saving Time by David Prerau (Thunder’s Mouth Press; $23.00; ISBN 1-56025-655-9)

• Spring Forward by Michael Downing (Shoemaker & Hoard; $23.00; ISBN 1-59376-053-1)

External links

• A Brief History of DST
• Straightforward discussion of DST
• End Daylight Saving Time (history and analysis of the practice)
• EU directive 2000/84/EC
• Daylight saving time, its history and why we use it - from U.S. National Institute of Science and Technology
• DST changeover times throughout the world
• Sources for daylight saving time data, including histories and predictions
• Summer Time by JR Stockton. With future changeover dates EU (until 2007 final, from then extrapolating)
• World Time Server
• Sleep deficit and accidents
• National Association of Standard Time
• Greenwich Mean Time: World Time
• PhotoSydney: Daylight Saving examines daylight saving in Australia.