
#REDIRECT Daylight saving time
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 standard official time. "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. The Time zone#List of time zones and contained areas has information on which areas do or do not observe DST. The expression '''daylight saving''s'' time''' (with the extra "s") is a common alternate form but is not considered to be proper English because "saving" is used here as a Verbal_noun describing a single type of activity. ==Origin== It is sometimes asserted that DST was first proposed by Benjamin Franklin in a letter to the editors of the ''Journal of Paris'' [http://webexhibits.org/daylightsaving/franklin3.html]. However, the article was humorous; Franklin was not proposing DST, but rather that people should get up and go to bed earlier. It was first seriously proposed by William Willett in the "Waste of Daylight" [http://webexhibits.org/daylightsaving/willett.html], published in 1907, but he was unable to get the Parliament of the United Kingdom to adopt it, despite considerable lobbying. ==History== The idea of daylight saving time was first put into practice by the Germany government during the World War I between April 30, 1916 and October 1, 1916. Shortly afterward, the United Kingdom followed suit, first adopting DST between May 21, 1916 and October 1, 1916. Then on March 19, 1918 the Congress of the United States 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so unpopular (mostly because people rose earlier and went to bed earlier than in modern times) that the law was later repealed. Daylight saving time was reinstated in the United States on February 9, 1942, again as a wartime measure to conserve resources, this time in order to fight World War II. This remained in effect until the war began winding down and the requirement was removed on September 30, 1945. From 1945 to 1966, there was no federal law about 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 and 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). The 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 response to the 1973 energy crisis, daylight saving 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. According to a report from CNN [http://www.cnn.com/2005/POLITICS/04/07/daylight.saving.ap/index.html], the U.S. Congress may again pass a bill extending daylight saving time by two months, beginning on the first Sunday in March and ending on the last Sunday in November. The purpose of this bill is to address increasing energy usage, allowing the nation to conserve more energy than it would otherwise. ==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. 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. USD28 million in traffic costs. [http://www.boulder.nist.gov/timefreq/general/daylightsavingtime.html] ==Criticism of DST== DST is not universally accepted; many localities do not observe it. Opponents claim that there's 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. 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 AC 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. Some campaigners in United Kingdom 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. 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. ===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: * 77 counties, most of the state, are on ''Eastern'' Standard Time but ''do not'' use DST; * 5 counties near Chicago 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 29th, 2005, the Indiana legislature voted to end their holdout and begin observing Daylight Saving Time in 2006, however what time zone the state will be placed in is unknown pending federal hearings [http://www.indystar.com/apps/pbcs.dll/article?AID=/20050429/NEWS02/504290510]. ==DST around the world== 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 Nation 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. 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). 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. Legislation pending in Congress would extend DST from the first Sunday in March until the first Sunday in November. The proposed change to help save energy faces little opposition and is expected to pass. All countries in Europe, except Iceland as already noted, observe DST and switch at the same universal time (01:00 UTC) in all five zones, going from 22:00/00:00/01:00/02:00/03:00 LST to 23:00/01:00/02:00/03:00/04:00 LDT simultaneously on the last Sunday in March, and back from 23:00/01:00/02:00/03:00/04:00 LDT to 22:00/00:00/01:00/02:00/03:00 LST on the last Sunday in October (formerly September) (for the European Union, except the overseas territories, per EU directive 2000/84/EC [http://europa.eu.int/eur-lex/pri/en/oj/dat/2001/l_031/l_03120010202en00210022.pdf]; for some of Greenland: the Saturday before). As Iceland is in the UTC+0 time zone, while their longitude would indicate UTC−1, they may be said to be on DST all year round. 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. 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. 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 referendum 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. 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. 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, Alberta/Saskatchewan, 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 Zone, which is the time used by Alberta. ==Mnemonic== The mnemonic "spring ahead, fall behind" tells us how to reset clocks when the time changes, regardless of hemisphere. 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. ==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 [http://www.cfa.vic.gov.au/ Country Fire Authority] of Victoria in Australia has been running a program called "Change Your Clock, Change Your Smoke Alarm Battery" for several years. ==See also== *British Summer Time *European Summer Time ==Books== *[http://seizethedaylight.com ''Seize the Daylight'' by David Prerau] (Thunder’s Mouth Press; $23.00; ISBN 1-56025-655-9) *[http://www.shoemakerhoard.com/catalog/spring.html ''Spring Forward'' by Michael Downing] (Shoemaker & Hoard; $23.00; ISBN 1-59376-053-1) ==External links== *[http://www.seizethedaylight.com/dst/ A Brief History of DST] *[http://webexhibits.org/daylightsaving/ Straightforward discussion of DST] *[http://www.standardtime.com/ End Daylight Saving Time] (history and analysis of the practice) *[http://europa.eu.int/eur-lex/pri/en/oj/dat/2001/l_031/l_03120010202en00210022.pdf EU directive 2000/84/EC] *[http://www.boulder.nist.gov/timefreq/general/daylightsavingtime.html Daylight saving time, its history and why we use it] - from U.S. National Institute of Science and Technology *[http://www.timeanddate.com/time/aboutdst.html DST changeover times throughout the world] *[http://www.twinsun.com/tz/tz-link.htm Sources for daylight saving time data, including histories and predictions] *[http://www.merlyn.demon.co.uk/uksumtim.htm Summer Time] by JR Stockton. With future changeover dates EU (until 2007 final, from then extrapolating) *[http://www.worldtimeserver.com/ World Time Server] *[http://www.mcmaster.ca/inabis98/occupational/coren0164/two.html Sleep deficit and accidents] *[http://www.nast.tk National Association of Standard Time] *[http://wwp.greenwichmeantime.com/ Greenwich Mean Time: World Time] *[http://photosydney.blogspot.com/2004/12/daylight-saving.html PhotoSydney: Daylight Saving] examines daylight saving in Australia. Time zones th:เวลาออมแสง
On Template:March 19 selected anniversaries ------- ==Spring Forward, Fall Back== :"The mnemonic "Spring forward, Fall back", tells how to reset clocks in the Northern hemisphere when the time switches." Maybe I'm staying up too late... :-) ...but isn't this correct also for the Southern Hemisphere? That is, don't you advance one hour in the springtime, whenever spring occurs in your hemisphere? -- user:Rootbeer : I think so. Spring is always the lengthening of days. In other words, seasons are specific to a hemisphere, but months are the same everywhere. July is a Winter month in New Zealand, as strange as that sounds to northerners! -- User:Tarquin ::It would be correct for both hemispheres, but for the fact that all English speakers in the Southern hemisphere say "autumn" rather than "fall". Except American tourists, of course. :) User:Tim Starling 04:24 Nov 28, 2002 (UTC) ==Usefulness or lack thereof== It has always struck me as odd to "save" daylight in the summer months, when there's so much of it anyway! There are campaigns in the UK to switch to DST all year round, that is to switch to GMT+1, as in winter months schoolchildren walk home around 16:00 and this is just when night falls, the worst time of the day for visibility on the roads. -- user:Tarquin :Or, they could change the school schedules to a more appropriate time without changing every clock in the country. Am I the only one who thinks daylight saving time is like trying to reduce traffic accidents by recalibrating all the speedometers to make people think they're going faster than they really are? --User:Brion VIBBER 02:25 Sep 10, 2002 (UTC) ::My comments on this were edited a bit. I originally wrote "Campaigners in Britain would like the country to stay on BST all year round, or to adopt Central European Time". This was altered to read "Campaigners in Britain would like the country to stay on BST all year round, or in other words, adopt Central European Time". But that's not quite what I meant. I meant EITHER stay on fixed daylight saving time all year round, adding one hour to GMT, OR adopt European time, adding an extra hour to winter time and two hours to summer. - Lee M. :::Fixed. - User:Patrick 22:26, 26 Oct 2003 (UTC) ==5th Grade Americentric== "5th grade" - this should be changed to an age to be comprehensible to those of outside the USA. -- Khendon :Agreed. -- User:Tarquin ==Usage error?== How is "Daylight Savings Time" not a usage error? It doesn't make any kind of grammatical sense! - User:Khendon :Does "savings account" not make any kind of grammatical sense? --User:Brion VIBBER Yes, it does. Savings is a noun meaning a fund of money - a savings account is an account of savings. Daylight Saving Time is the Time used to Save Daylight. What does Daylight Savings Time mean? - User:Khendon :So when the local supermarket offers me MAJOR SAVINGS, it's offering to give me a fund of money over 18 years of age? Daylight Savings Time is, obviously enough to anyone who can parse English, the Time when you make Savings in Daylight. --User:Brion VIBBER re: google searches; it's not enough to do a naive page count. Actually look at the results - searching for the with-s variant turns up many pages saying that the correct spelling is without-s. In any case, who decided any illiterate who can make a web page gets an equal vote? -- User:Khendon :If an overwhelmingly large portion of the population didn't say it that way, pedants wouldn't feel the need to combat it at every turn. And if "illiterates" aren't enough for you, how about [http://www.bartleby.com/61/65/D0046500.html a dictionary]? --User:Brion VIBBER :: "savings" are things one stocks and keeps. Unless you're not telling us something, Brion, or should I say Doctor Who!, no-one can make "savings" of time. We are "sort of) saving it in the sense of avoiding its waste. -- User:Tarquin :::That's what makes it so cruelly deceptive -- you may save an hour once a year, but you give it up again six months later. :) I'll point out that, whether "saving" or "savings", there's exactly as much daylight no matter what you do to your clock. You don't save squat. --User:Brion VIBBER ----- "pedants" is it neutral in english ? ---- Dictionaries aren't authorities on English usage either, Brion; most are overtly descriptive and not prescriptive in nature, and even those that aren't admittedly so are so in practice. All that aside, what's wrong with the present state of the article--it uses the preferred form "saving", and mentions that "savings" is commonly used but often considered wrong. Isn't that exactly what an article on the subject should do? --User:Lee Daniel Crocker :Exactly my point, Lee. Yes, the article is precisely correct -- now. Previously it was overtly prescriptive, saying ''The expression "Daylight savings time" (with the extra s) is a common usage error.'' One might as well say that "soft drink" in reference to a carbonated, sweetened beverage is a common usage error which occurs frequently in the Midwest... I'm not sure I've ''ever'' in my life heard someone say "daylight saving time" without the s. --User:Brion VIBBER :Correct, incorrect. The fact is, the mechanism was originally called daylight saving time, but the only people who care if you say daylight savings time are pedants. A real pedant, me for instance, would say that it should be daylight-saving time. So, except for the tragedy of the missing hyphen, the article is perfectly correct as it stands. User:Ortolan88 ==Date of intro in USA== Right now the article seems to state two different dates for the US introduction of DST: 1918 and 1942. Which one is correct? :It turns out both are correct. I've added much more background. -- User:Minesweeper 09:01 22 May 2003 (UTC) Note that not every European country observes daylight saving time in the normal sense. Iceland is on constant +1 daylight saving time, which is important during the 4 hours of daylight we get around Christmas. Anyone know the details of British double summer time (and also I believe German double summer time), that existed for part of the summer during WWII? User:Mintguy ==Time zone source material== I'd like to get a set of rules for major population centers, especially for English-speaking areas (like Japan, where people study ESL). I want to make some GPL software that tells the user what time it is in his friend or business associate's time zone, taking into account daylight saving time oddities. Especially when right near boundary conditions, like the last week in March or first week in April, when one might not be sure whether the Other Person is observing the same rules. I'm going to make the software not only give you the other fellow's local time, but also display whichever rules apply. So, if I'm in New York and you're in Chicago in the middle of the summer, we're both using the same rules -- so nothing special, you're just an hour behind: my 5:00 P.M is your 4:00 P.M. But if you're in Indiana, where some counties have opted out of DST... Or if it's soon after midnight, the last weekend in October and NYC has just set its clocks back -- but you're in Denver and haven't set yours back... Or Cuba, which "springs forward" an April 1st... or those puzzling folks in Europe who do it a week early each spring... So, please add all this info to the article, or find me a nice juicy link and all add it myself! --User:Ed Poor 16:51, 27 Oct 2003 (UTC) : Nice Juicy Link (TM): http://www.twinsun.com/tz/tz-link.htm -- User:CatherineMunro 05:03, 1 Apr 2004 (UTC) ==Time shifts== ''...going from 22pm/0/1/2/3am LST to 23pm/1/2/3/4am LDT simultaneously on the last Sunday in March, and back from 23pm/1/2/3/4am LDT to 22pm/0/1/2/3am LST on the last Sunday in October...'' :Call me stupid, but is there some new system of time we should be using that has 22pm and 23pm, and in which 23pm is equivalent to 0am? What have I missed? - User:Mark Ryan 04:52, 2 Dec 2003 (UTC) ::I fixed the first, but do not understand "23pm is equivalent to 0am": one zone is skipped, because it does not apply. - User:Patrick 19:48, 2 Dec 2003 (UTC) ::: 22, 23, etc shouldn't be labeled am or pm, should they? The whole point is to avoid the ambiguity of 12-hour clock am/pm-ness.... The 24-hour clock article doesn't explicitly specify but doesn't use them either. User:CatherineMunro 05:03, 1 Apr 2004 (UTC) ==12 hour vs 24 hour again== User 81.225.47.48 changed ''Brazilian DST starts at 12:00AM of a October (rarely November) Sunday'' to ''Brazilian DST starts at noon of a October (rarely November) Sunday'' in order to be "less ambiguous". True, "noon" is less ambiguous than either "12:00 AM" or "12:00 PM" would be, but is this really correct? Most of the world switches to DST in the night; is Brazil an exception here?? There is no link to a Portuegues article on this topic, and the is to brief to give any details. Btw, Brazil stretches over 3 time zones. If all of them change to DST at noon, that must be a mess... Also, I don't think that going from ''ends at 2:00 AM on the last Sunday in October'' to ''ends at 2 :00 on the last Sunday in October'' helps "unambiguation". You could argue that such changes does not introduce any new ambiguity, since everybody will understand that the 24 hour clock is used, but my experience tells me that not everybody is used to the 24 hour clock. User:Aleph4 21:58, 16 Feb 2005 (UTC) I went ahead and reverted 81.225.47.48's changes. 12:00 AM, although confusing to some, means exactly one thing, midnight. ==History of DST in specific areas== I'm familiar with the "rules" of daylight savings time. However, I'm searching for specific answers about its observation in two locations in two different months and years. Can anyone tell me whether or not daylight savings time was observed in (1)Barbourville, Kentucky, USA (Knoxville County) in June of 1950, and (2)Shreveport, Louisiana USA in September of 1954? Or can anyone refer me to a source that has detailed information about which states, counties, or parishes chose daylight savings time during the years when the locals could choose for themselves (i.e., 1945-1966)? Any suggestions would be greatly appreciated.--Miranda Moore : You may want to take this to the Wikipedia:Reference desk, where questions like this are better suited. User:Dysprosia 03:32, 17 Dec 2003 (UTC) :: It's not cheap ($195), but there's a comprehensive book about the history of time changes by locale, designed for astrologers, of all things. (Maybe you can find an older edition on eBay or in used bookstores.) It is available by computer download here: http://astrocom.com/software/pcatlas.php -- User:CatherineMunro 05:03, 1 Apr 2004 (UTC) == Sir Sanford Fleming -- first proposed daylight savings time, and not whoever the bloke in the article is. I'm not sure when he did it (sometime in the 1880's) or I'd fix it myself. : He was the one who invented it for the railroads, which ARE mentioned in the article. I'll add him in. -- User:CatherineMunro 05:03, 1 Apr 2004 (UTC) == Auto safety == Interesting to read about a "spike in the number of severe auto accidents". This is the opposite of the effect I've heard from DST proponents: it's usually claimed that DST saves lives, since many more people will commute during daylight, when it's safer to drive. (Anybody have a source for this?) Also, the study I found that states that auto accidents spike due to DST (http://www.bnsf.com/media/articles/2004/04/2004-04-01-c.html?index=/media/articles/index.html) says that auto accidents dropped by the same amount when daylight savings ends (and people get extra sleep). So making a spike in auto accidents sound like a simple case-against sounds quite misleading. == DST == Can someone tell the server about a phenomenon called Daylight Savings Time, so I don't have so switch between GMT-5 and GMT-6 every time we have DST? : The specific date, direction, and amount of shift to "correct" for the changing light levels is very much location-specific; indeed, some places don't have any need of it at all. The server is in GMT (well, an approximation of UTC-1, AIUI); the clocks change but twice a year, and I'm sure that you can cope. In fact, I don't have it change, and use my head to do the offset instead (well, 'tis only an hour for me, so...). : User:Jdforrester User_talk:Jdforrester ::It would be simple. There could be a check box that says "Please auto-correct my time shift for daylight savings time", so it would only do it if you wanted it to. If there are different types of daylight savings times around the globe, it could have an option to select which type. Worth submitting a feature request for, I might do it soon if nobody else has. User:Siroxo—User:SiroxoUser talk:SiroxoUser:Siroxo 04:26, Aug 2, 2004 (UTC) ::: Over here in Israel, there is a vote taking place every year, that determines the DST shift in/shift out. Computer modelling of our politicians to predict what they are going to vote on would be mostly welcome. :-) Seriously, a common practice is using NTP to feed off a trusted server, and once it jumps, you know that the daylight savings jumped. The server is manually updated. Some systems just have some hardwired approximate default dates, so around the shift they give wrong time for about a month in the worst case. User:BACbKA 20:58, 2 Aug 2004 (UTC) ::::You use NTP to transmit ''local times'' and not UTC? Oh, the horror, the horror... User:David.Monniaux 14:07, 8 Aug 2004 (UTC) ::::Israel appears to define the start of DST in the common calendar and the end by the Hebrew calendar, which actually makes sense. Because of a Sunday to Thursday workweek, Israel starts and ends Friday. User:Ab762 22:09, 5 Apr 2005 (UTC) :: Most open source Unix systems use a library produced by NIH that knows about virtually every set of timezone rules on earth and is capable of translating things like US/Eastern + an offset in GMT into the local time and date. This library is extremely well maintained, the timezone files cover almost all jurisdictions on the planet, and updates come out several times a year. The code is all open source. There is no reason not to use it. --User:Pmetzger 21:03, 3 Aug 2004 (UTC) ==Xerox timezone converter app is down== The link [http://sandbox.xerox.com/stewart/tzconvert.cgi Time Zone Converter] is down as of 4 November 2004. I have hidden the same in the article. --User:maha_ts 10:44, 4 Nov 2004 (UTC) ==So how exactly is DST useful ?== Can the article have some statistics or have a link to some statistics that list out the sunrise and sunset times of major countries, for different months of the year. I live in the tropics, and haven't experienced DST. Hence its difficult for me to understand exactly how people (in the temperate zone) find DST useful and how it affects their daily life. User:Jay 10:05, 18 Feb 2005 (UTC) :I've lived in Hawaii most of my life (with no DST) but went to school in the U.S. Pacific Northwest, which is around 45 degrees north latitude. That far north, sunrise usually happens at around 05:00 (DST) and the sun sets at around 21:00 (DST)...that means that you could go for an evening stroll while it's completely lighted. I'm sure there are some calculators around that allow you to calculate sunrise and sunset given latitude and longitude... User:KeithH 07:28, 25 Mar 2005 (UTC) :The big advantage of DST is that it "transfers" an hour or so from early in the day when few people are up and about to the evening, when activity is high. In effect there is a "free" hour of sunlight, with consequent savings in electicity usage. During WW2 the UK experienced double DST, when the clocks were advanced two hours rather than one, to take advantage of the very long hours of sunlight in high summer. Personally, I enjoy the long summer evenings, and it is pleasant to take a stroll or have a relaxing drink outside at that time of year, using time that would otherwise be dark. A disadvantage for parents of small children is that it can be harder to get them to sleep while the sun is still quite high in the sky. User:Skyring 08:55, 23 May 2005 (UTC) == I challenge a statement made in the main article == 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. … This would make winter evenings longer, thereby reducing traffic accidents and cases of seasonal affective disorder. It wouldn't necessarily reduce SAD. I suffer from it, and for me the biggest problem is the darkness in the morning. Many SAD sufferers, including myself, need the dawn to tell our bodies that it is time to wake up and hence have difficulty waking up during the winter. We can also have difficulty staying awake during the day as, even though we may have had eight hours as recommended, our bodies are still convinced that we were woken up in the middle of the night. Granted, the above problems can be worked around with a dawn simulator, but that does not excuse adopting a time system that would trigger new cases of SAD and/or worsen existing ones. The existence of a treatment for any given illness does not make it ethically acceptable to adopt an avoidable practise which will trigger that illness, and SAD is no exception.~~~~ ") But what do you disagree with? It says "some campaigners" and it says the number of cases of SAD would be reduced. Not you, perhaps, but some. User:Psb777 01:13, 19 Feb 2005 (UTC)
== Saving/savings and such confusion ==
I suspect that hyphenating the title would make it more obvious as to what everything means; "daylight-saving time". User:Porge 09:57, Mar 21, 2005 (UTC)
== Sir Sandford Fleming ==
Does the paragraph on Sir Sandford Fleming belong in this article? I don't think so. He was involved in the creation of "standard time", i.e., time zones, but he didn't have anything to do with daylight saving time. User:Indefatigable 23:40, 25 Mar 2005 (UTC)
== DST Errata? ==
What technically applies to bars and television schedules?
For instance in the fall, what do clocks jump to when it turns 2am?
Do they go to 1am?, or do the clocks go from 2:59 to 2:00?
What happens to broadcasts for this extra hour (besides the pragmatic answer of "infomercials").
What about bars? They variously seem to stay open an extra hour, lending credence to the former conclusion that clocks go from 1:59am to 1:00am, then resume normal progression.
What happens in the case of the jump in spring, from 02:00 to 03:00? Do the clocks go from 01:59 to 03:00? As interesting as the thought exercise is, I had much better things to do than staring at a clock to figure this out. Also, I didn't realise it was DST in order to look (I noticed my alarm clock was an hour and 10 minutes behind my computer clock, instead of just 10 minutes).
Is there a "universal time" such that no time zones or DST effects occur? Something like computers do with "Seconds Elapsed since 1970". I can see such a thing being extremely critical in time sensitive calculations such as astronomy. I realise astronomers usually don't care about to-the-second accuracy, but to-the-hour accuracy makes more sense, and in the context of DST, that's precisely where the inaccuracies occur. This is illustrated by me asking what happened 48 hours ago at 1am on Month 3rd, and it just became DST on Month 2nd. I probably mean an absolute 48 hours ago, which would be 1am of Month 1st, not at 12am of Month 1st. If I were simply running calculations based on a clock, not realising or figuring in for DST, this accuracy would crop up (I'd be determining what happened 49 hours ago, not 48 as required). However, this error does cancel out if the time interval crosses the boundary from DST to Standard again. There's also some question of what kinds of errors occur when times involved fall right on these boundaries, particularly when the boundary points are at the ends of the time interval. It almost seems like the sort of ambiguity that occurs when a programmer has to make an arbitrary decision about something.
Have DST to Standard time boundaries every caused any actual problems in the real world, besides people not getting enough sleep and getting into car accidents or not doing well at work?
As far as traffic safety goes, personally, I'd come to the knee-jerk conclusion that night driving is safer than daytime. My rationale is very simple, so simple you'd say "Well, why didn't I think of that?" or the ever-perrenial "I could have thought of that."
Rationale: There's less traffic on the road at night, leading to less vehicle-vehicle collisions.
This is especially true in less populated areas, but also somewhat applies in large cities as well.
Of course, this neglects the problems of drowsy drivers running into more stationary objects, particularly by the ever-present collision spike around 02:15, when the drunks are kicked out of the bars (whether or not they're fit to drive) by law. Of course, if you're a night-owl like me, night driving doesn't pose much of a problem. Of course, gas being as pricy as it is now, I don't even do much driving anymore, when I can help it. User:JD 09:07, 3 Apr 2005 (UTC)
:[http://webexhibits.org/daylightsaving/b.html Daylight Saving Time at WebExhibits] and [http://www.timeanddate.com/time/aboutdst.html About Daylight Saving Time] address some of your questions.
:The "universal time" without time zones or DST is indeed Universal Time, also known as Greenwich Mean Time, more particularly Coordinated Universal Time. But the latter does have leap seconds that seem to interrupt the normal flow of clock time having only 60 seconds per minute, due to Earth's slowing rotation (23:59:59 → 23:59:60 → 00:00:00 UTC). — User:Joe Kress 00:02, Apr 4, 2005 (UTC)
==Queensland==
Queensland did in fact experiment with DST, for 1 or possibly 2 years, in the late 1960s or early 1970s. I know because I lived there at the time and it was very topical. The then Premier Sir Joh Bjelke-Petersen decided not to repeat it after then. The story goes that his political supporters, a large proportion of whom were rural dwellers, did not like DST because "the cows get confused and don't produce enough milk", or "the extra sunshine fades the curtains". These are no doubt apocryphal, but still say something about the kind of people we're dealing with here. Queensland has therefore been out of step with the rest of the eastern seabord for 35 years (some would say forever). User:JackofOz 04:43, 11 May 2005 (UTC)
I lived in Queensland at the time, and thought that it meant I'd get an extra hour to lie in bed of a morning and read. Boy, was I wrong!
The reason it was dropped wasn't political but geographical. Queensland is one of the more decentralised States, and consequently a large percentage of the population lives north and west of the capital city of Brisbane, which is at the extreme south east corner of the State. With the Tropic of Capricorn only a few hundred kilometres north of Brisbane, a large amount of the State is in the tropics where the benefits of Daylight Saving are minimal. The coastline trends north-westerly, exacerbating the problem the further north one goes. Residents of Mount Isa, for example, found that in summer they were having to get up before dark, and schoolchildren were walking home during the hottest part of the day. There was little benefit in it for a great many Queenslanders, and rather than divide the State into two time zones, the scheme was dropped. It must be remembered that Tasmania, the southernmost State, begins DST earlier and ends later than the mainland States, and that the permanent difference in time zones between (say) Victoria and South Australia causes no problems. User:Skyring 09:06, 23 May 2005 (UTC)
==DST in Winter==
I've long thought that in a hot and sunny country like Australia, we should have DST, but rather than doing it in summer, we should do it in winter instead. Australia is already way too sunny, as evidenced by the highest rate of skin cancers in the world. We simply don't need any more daylight in our lives in summer, we have too much already. But in winter we could definitely do with some more daylight at the end of the day, whereas currently we tend to go home in at best fading light, or more usually darkness. Yes, it would mean we'd be getting up in darkness, but that's true for most people anyway so there's no loss there. I've been on this particular soapbox for at least 30 years, but so far our governments have failed to heed my brilliant advice. User:JackofOz 04:43, 11 May 2005 (UTC)
See other meanings of words starting from letter:
Words begining with Daylight_saving_time:
Daylight-saving_time
Daylight_Saving_Time
Daylight_saving_time
Daylight_saving_time
Daylight Saving Time
#REDIRECT Daylight saving time
Daylight saving time
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 standard official time. "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. The Time zone#List of time zones and contained areas has information on which areas do or do not observe DST. The expression '''daylight saving''s'' time''' (with the extra "s") is a common alternate form but is not considered to be proper English because "saving" is used here as a Verbal_noun describing a single type of activity. ==Origin== It is sometimes asserted that DST was first proposed by Benjamin Franklin in a letter to the editors of the ''Journal of Paris'' [http://webexhibits.org/daylightsaving/franklin3.html]. However, the article was humorous; Franklin was not proposing DST, but rather that people should get up and go to bed earlier. It was first seriously proposed by William Willett in the "Waste of Daylight" [http://webexhibits.org/daylightsaving/willett.html], published in 1907, but he was unable to get the Parliament of the United Kingdom to adopt it, despite considerable lobbying. ==History== The idea of daylight saving time was first put into practice by the Germany government during the World War I between April 30, 1916 and October 1, 1916. Shortly afterward, the United Kingdom followed suit, first adopting DST between May 21, 1916 and October 1, 1916. Then on March 19, 1918 the Congress of the United States 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 earlier and went to bed earlier than in modern times) that the law was later repealed. Daylight saving time was reinstated in the United States on February 9, 1942, again as a wartime measure to conserve resources, this time in order to fight World War II. This remained in effect until the war began winding down and the requirement was removed on September 30, 1945. From 1945 to 1966, there was no federal law about 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 and 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). The 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 response to the 1973 energy crisis, daylight saving 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. According to a report from CNN [http://www.cnn.com/2005/POLITICS/04/07/daylight.saving.ap/index.html], the U.S. Congress may again pass a bill extending daylight saving time by two months, beginning on the first Sunday in March and ending on the last Sunday in November. The purpose of this bill is to address increasing energy usage, allowing the nation to conserve more energy than it would otherwise. ==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. 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. USD28 million in traffic costs. [http://www.boulder.nist.gov/timefreq/general/daylightsavingtime.html] ==Criticism of DST== DST is not universally accepted; many localities do not observe it. Opponents claim that there's 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. 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 AC 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. Some campaigners in United Kingdom 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. 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. ===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: * 77 counties, most of the state, are on ''Eastern'' Standard Time but ''do not'' use DST; * 5 counties near Chicago 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 29th, 2005, the Indiana legislature voted to end their holdout and begin observing Daylight Saving Time in 2006, however what time zone the state will be placed in is unknown pending federal hearings [http://www.indystar.com/apps/pbcs.dll/article?AID=/20050429/NEWS02/504290510]. ==DST around the world== 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 Nation 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. 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). 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. Legislation pending in Congress would extend DST from the first Sunday in March until the first Sunday in November. The proposed change to help save energy faces little opposition and is expected to pass. All countries in Europe, except Iceland as already noted, observe DST and switch at the same universal time (01:00 UTC) in all five zones, going from 22:00/00:00/01:00/02:00/03:00 LST to 23:00/01:00/02:00/03:00/04:00 LDT simultaneously on the last Sunday in March, and back from 23:00/01:00/02:00/03:00/04:00 LDT to 22:00/00:00/01:00/02:00/03:00 LST on the last Sunday in October (formerly September) (for the European Union, except the overseas territories, per EU directive 2000/84/EC [http://europa.eu.int/eur-lex/pri/en/oj/dat/2001/l_031/l_03120010202en00210022.pdf]; for some of Greenland: the Saturday before). As Iceland is in the UTC+0 time zone, while their longitude would indicate UTC−1, they may be said to be on DST all year round. 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. 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. 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 referendum 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. 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. 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, Alberta/Saskatchewan, 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 Zone, which is the time used by Alberta. ==Mnemonic== The mnemonic "spring ahead, fall behind" tells us how to reset clocks when the time changes, regardless of hemisphere. 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. ==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 [http://www.cfa.vic.gov.au/ Country Fire Authority] of Victoria in Australia has been running a program called "Change Your Clock, Change Your Smoke Alarm Battery" for several years. ==See also== *British Summer Time *European Summer Time ==Books== *[http://seizethedaylight.com ''Seize the Daylight'' by David Prerau] (Thunder’s Mouth Press; $23.00; ISBN 1-56025-655-9) *[http://www.shoemakerhoard.com/catalog/spring.html ''Spring Forward'' by Michael Downing] (Shoemaker & Hoard; $23.00; ISBN 1-59376-053-1) ==External links== *[http://www.seizethedaylight.com/dst/ A Brief History of DST] *[http://webexhibits.org/daylightsaving/ Straightforward discussion of DST] *[http://www.standardtime.com/ End Daylight Saving Time] (history and analysis of the practice) *[http://europa.eu.int/eur-lex/pri/en/oj/dat/2001/l_031/l_03120010202en00210022.pdf EU directive 2000/84/EC] *[http://www.boulder.nist.gov/timefreq/general/daylightsavingtime.html Daylight saving time, its history and why we use it] - from U.S. National Institute of Science and Technology *[http://www.timeanddate.com/time/aboutdst.html DST changeover times throughout the world] *[http://www.twinsun.com/tz/tz-link.htm Sources for daylight saving time data, including histories and predictions] *[http://www.merlyn.demon.co.uk/uksumtim.htm Summer Time] by JR Stockton. With future changeover dates EU (until 2007 final, from then extrapolating) *[http://www.worldtimeserver.com/ World Time Server] *[http://www.mcmaster.ca/inabis98/occupational/coren0164/two.html Sleep deficit and accidents] *[http://www.nast.tk National Association of Standard Time] *[http://wwp.greenwichmeantime.com/ Greenwich Mean Time: World Time] *[http://photosydney.blogspot.com/2004/12/daylight-saving.html PhotoSydney: Daylight Saving] examines daylight saving in Australia. Time zones th:เวลาออมแสง
Daylight saving time
On Template:March 19 selected anniversaries ------- ==Spring Forward, Fall Back== :"The mnemonic "Spring forward, Fall back", tells how to reset clocks in the Northern hemisphere when the time switches." Maybe I'm staying up too late... :-) ...but isn't this correct also for the Southern Hemisphere? That is, don't you advance one hour in the springtime, whenever spring occurs in your hemisphere? -- user:Rootbeer : I think so. Spring is always the lengthening of days. In other words, seasons are specific to a hemisphere, but months are the same everywhere. July is a Winter month in New Zealand, as strange as that sounds to northerners! -- User:Tarquin ::It would be correct for both hemispheres, but for the fact that all English speakers in the Southern hemisphere say "autumn" rather than "fall". Except American tourists, of course. :) User:Tim Starling 04:24 Nov 28, 2002 (UTC) ==Usefulness or lack thereof== It has always struck me as odd to "save" daylight in the summer months, when there's so much of it anyway! There are campaigns in the UK to switch to DST all year round, that is to switch to GMT+1, as in winter months schoolchildren walk home around 16:00 and this is just when night falls, the worst time of the day for visibility on the roads. -- user:Tarquin :Or, they could change the school schedules to a more appropriate time without changing every clock in the country. Am I the only one who thinks daylight saving time is like trying to reduce traffic accidents by recalibrating all the speedometers to make people think they're going faster than they really are? --User:Brion VIBBER 02:25 Sep 10, 2002 (UTC) ::My comments on this were edited a bit. I originally wrote "Campaigners in Britain would like the country to stay on BST all year round, or to adopt Central European Time". This was altered to read "Campaigners in Britain would like the country to stay on BST all year round, or in other words, adopt Central European Time". But that's not quite what I meant. I meant EITHER stay on fixed daylight saving time all year round, adding one hour to GMT, OR adopt European time, adding an extra hour to winter time and two hours to summer. - Lee M. :::Fixed. - User:Patrick 22:26, 26 Oct 2003 (UTC) ==5th Grade Americentric== "5th grade" - this should be changed to an age to be comprehensible to those of outside the USA. -- Khendon :Agreed. -- User:Tarquin ==Usage error?== How is "Daylight Savings Time" not a usage error? It doesn't make any kind of grammatical sense! - User:Khendon :Does "savings account" not make any kind of grammatical sense? --User:Brion VIBBER Yes, it does. Savings is a noun meaning a fund of money - a savings account is an account of savings. Daylight Saving Time is the Time used to Save Daylight. What does Daylight Savings Time mean? - User:Khendon :So when the local supermarket offers me MAJOR SAVINGS, it's offering to give me a fund of money over 18 years of age? Daylight Savings Time is, obviously enough to anyone who can parse English, the Time when you make Savings in Daylight. --User:Brion VIBBER re: google searches; it's not enough to do a naive page count. Actually look at the results - searching for the with-s variant turns up many pages saying that the correct spelling is without-s. In any case, who decided any illiterate who can make a web page gets an equal vote? -- User:Khendon :If an overwhelmingly large portion of the population didn't say it that way, pedants wouldn't feel the need to combat it at every turn. And if "illiterates" aren't enough for you, how about [http://www.bartleby.com/61/65/D0046500.html a dictionary]? --User:Brion VIBBER :: "savings" are things one stocks and keeps. Unless you're not telling us something, Brion, or should I say Doctor Who!, no-one can make "savings" of time. We are "sort of) saving it in the sense of avoiding its waste. -- User:Tarquin :::That's what makes it so cruelly deceptive -- you may save an hour once a year, but you give it up again six months later. :) I'll point out that, whether "saving" or "savings", there's exactly as much daylight no matter what you do to your clock. You don't save squat. --User:Brion VIBBER ----- "pedants" is it neutral in english ? ---- Dictionaries aren't authorities on English usage either, Brion; most are overtly descriptive and not prescriptive in nature, and even those that aren't admittedly so are so in practice. All that aside, what's wrong with the present state of the article--it uses the preferred form "saving", and mentions that "savings" is commonly used but often considered wrong. Isn't that exactly what an article on the subject should do? --User:Lee Daniel Crocker :Exactly my point, Lee. Yes, the article is precisely correct -- now. Previously it was overtly prescriptive, saying ''The expression "Daylight savings time" (with the extra s) is a common usage error.'' One might as well say that "soft drink" in reference to a carbonated, sweetened beverage is a common usage error which occurs frequently in the Midwest... I'm not sure I've ''ever'' in my life heard someone say "daylight saving time" without the s. --User:Brion VIBBER :Correct, incorrect. The fact is, the mechanism was originally called daylight saving time, but the only people who care if you say daylight savings time are pedants. A real pedant, me for instance, would say that it should be daylight-saving time. So, except for the tragedy of the missing hyphen, the article is perfectly correct as it stands. User:Ortolan88 ==Date of intro in USA== Right now the article seems to state two different dates for the US introduction of DST: 1918 and 1942. Which one is correct? :It turns out both are correct. I've added much more background. -- User:Minesweeper 09:01 22 May 2003 (UTC) Note that not every European country observes daylight saving time in the normal sense. Iceland is on constant +1 daylight saving time, which is important during the 4 hours of daylight we get around Christmas. Anyone know the details of British double summer time (and also I believe German double summer time), that existed for part of the summer during WWII? User:Mintguy ==Time zone source material== I'd like to get a set of rules for major population centers, especially for English-speaking areas (like Japan, where people study ESL). I want to make some GPL software that tells the user what time it is in his friend or business associate's time zone, taking into account daylight saving time oddities. Especially when right near boundary conditions, like the last week in March or first week in April, when one might not be sure whether the Other Person is observing the same rules. I'm going to make the software not only give you the other fellow's local time, but also display whichever rules apply. So, if I'm in New York and you're in Chicago in the middle of the summer, we're both using the same rules -- so nothing special, you're just an hour behind: my 5:00 P.M is your 4:00 P.M. But if you're in Indiana, where some counties have opted out of DST... Or if it's soon after midnight, the last weekend in October and NYC has just set its clocks back -- but you're in Denver and haven't set yours back... Or Cuba, which "springs forward" an April 1st... or those puzzling folks in Europe who do it a week early each spring... So, please add all this info to the article, or find me a nice juicy link and all add it myself! --User:Ed Poor 16:51, 27 Oct 2003 (UTC) : Nice Juicy Link (TM): http://www.twinsun.com/tz/tz-link.htm -- User:CatherineMunro 05:03, 1 Apr 2004 (UTC) ==Time shifts== ''...going from 22pm/0/1/2/3am LST to 23pm/1/2/3/4am LDT simultaneously on the last Sunday in March, and back from 23pm/1/2/3/4am LDT to 22pm/0/1/2/3am LST on the last Sunday in October...'' :Call me stupid, but is there some new system of time we should be using that has 22pm and 23pm, and in which 23pm is equivalent to 0am? What have I missed? - User:Mark Ryan 04:52, 2 Dec 2003 (UTC) ::I fixed the first, but do not understand "23pm is equivalent to 0am": one zone is skipped, because it does not apply. - User:Patrick 19:48, 2 Dec 2003 (UTC) ::: 22, 23, etc shouldn't be labeled am or pm, should they? The whole point is to avoid the ambiguity of 12-hour clock am/pm-ness.... The 24-hour clock article doesn't explicitly specify but doesn't use them either. User:CatherineMunro 05:03, 1 Apr 2004 (UTC) ==12 hour vs 24 hour again== User 81.225.47.48 changed ''Brazilian DST starts at 12:00AM of a October (rarely November) Sunday'' to ''Brazilian DST starts at noon of a October (rarely November) Sunday'' in order to be "less ambiguous". True, "noon" is less ambiguous than either "12:00 AM" or "12:00 PM" would be, but is this really correct? Most of the world switches to DST in the night; is Brazil an exception here?? There is no link to a Portuegues article on this topic, and the is to brief to give any details. Btw, Brazil stretches over 3 time zones. If all of them change to DST at noon, that must be a mess... Also, I don't think that going from ''ends at 2:00 AM on the last Sunday in October'' to ''ends at 2 :00 on the last Sunday in October'' helps "unambiguation". You could argue that such changes does not introduce any new ambiguity, since everybody will understand that the 24 hour clock is used, but my experience tells me that not everybody is used to the 24 hour clock. User:Aleph4 21:58, 16 Feb 2005 (UTC) I went ahead and reverted 81.225.47.48's changes. 12:00 AM, although confusing to some, means exactly one thing, midnight. ==History of DST in specific areas== I'm familiar with the "rules" of daylight savings time. However, I'm searching for specific answers about its observation in two locations in two different months and years. Can anyone tell me whether or not daylight savings time was observed in (1)Barbourville, Kentucky, USA (Knoxville County) in June of 1950, and (2)Shreveport, Louisiana USA in September of 1954? Or can anyone refer me to a source that has detailed information about which states, counties, or parishes chose daylight savings time during the years when the locals could choose for themselves (i.e., 1945-1966)? Any suggestions would be greatly appreciated.--Miranda Moore : You may want to take this to the Wikipedia:Reference desk, where questions like this are better suited. User:Dysprosia 03:32, 17 Dec 2003 (UTC) :: It's not cheap ($195), but there's a comprehensive book about the history of time changes by locale, designed for astrologers, of all things. (Maybe you can find an older edition on eBay or in used bookstores.) It is available by computer download here: http://astrocom.com/software/pcatlas.php -- User:CatherineMunro 05:03, 1 Apr 2004 (UTC) == Sir Sanford Fleming -- first proposed daylight savings time, and not whoever the bloke in the article is. I'm not sure when he did it (sometime in the 1880's) or I'd fix it myself. : He was the one who invented it for the railroads, which ARE mentioned in the article. I'll add him in. -- User:CatherineMunro 05:03, 1 Apr 2004 (UTC) == Auto safety == Interesting to read about a "spike in the number of severe auto accidents". This is the opposite of the effect I've heard from DST proponents: it's usually claimed that DST saves lives, since many more people will commute during daylight, when it's safer to drive. (Anybody have a source for this?) Also, the study I found that states that auto accidents spike due to DST (http://www.bnsf.com/media/articles/2004/04/2004-04-01-c.html?index=/media/articles/index.html) says that auto accidents dropped by the same amount when daylight savings ends (and people get extra sleep). So making a spike in auto accidents sound like a simple case-against sounds quite misleading. == DST == Can someone tell the server about a phenomenon called Daylight Savings Time, so I don't have so switch between GMT-5 and GMT-6 every time we have DST? : The specific date, direction, and amount of shift to "correct" for the changing light levels is very much location-specific; indeed, some places don't have any need of it at all. The server is in GMT (well, an approximation of UTC-1, AIUI); the clocks change but twice a year, and I'm sure that you can cope. In fact, I don't have it change, and use my head to do the offset instead (well, 'tis only an hour for me, so...). : User:Jdforrester User_talk:Jdforrester ::It would be simple. There could be a check box that says "Please auto-correct my time shift for daylight savings time", so it would only do it if you wanted it to. If there are different types of daylight savings times around the globe, it could have an option to select which type. Worth submitting a feature request for, I might do it soon if nobody else has. User:Siroxo—User:SiroxoUser talk:SiroxoUser:Siroxo 04:26, Aug 2, 2004 (UTC) ::: Over here in Israel, there is a vote taking place every year, that determines the DST shift in/shift out. Computer modelling of our politicians to predict what they are going to vote on would be mostly welcome. :-) Seriously, a common practice is using NTP to feed off a trusted server, and once it jumps, you know that the daylight savings jumped. The server is manually updated. Some systems just have some hardwired approximate default dates, so around the shift they give wrong time for about a month in the worst case. User:BACbKA 20:58, 2 Aug 2004 (UTC) ::::You use NTP to transmit ''local times'' and not UTC? Oh, the horror, the horror... User:David.Monniaux 14:07, 8 Aug 2004 (UTC) ::::Israel appears to define the start of DST in the common calendar and the end by the Hebrew calendar, which actually makes sense. Because of a Sunday to Thursday workweek, Israel starts and ends Friday. User:Ab762 22:09, 5 Apr 2005 (UTC) :: Most open source Unix systems use a library produced by NIH that knows about virtually every set of timezone rules on earth and is capable of translating things like US/Eastern + an offset in GMT into the local time and date. This library is extremely well maintained, the timezone files cover almost all jurisdictions on the planet, and updates come out several times a year. The code is all open source. There is no reason not to use it. --User:Pmetzger 21:03, 3 Aug 2004 (UTC) ==Xerox timezone converter app is down== The link [http://sandbox.xerox.com/stewart/tzconvert.cgi Time Zone Converter] is down as of 4 November 2004. I have hidden the same in the article. --User:maha_ts 10:44, 4 Nov 2004 (UTC) ==So how exactly is DST useful ?== Can the article have some statistics or have a link to some statistics that list out the sunrise and sunset times of major countries, for different months of the year. I live in the tropics, and haven't experienced DST. Hence its difficult for me to understand exactly how people (in the temperate zone) find DST useful and how it affects their daily life. User:Jay 10:05, 18 Feb 2005 (UTC) :I've lived in Hawaii most of my life (with no DST) but went to school in the U.S. Pacific Northwest, which is around 45 degrees north latitude. That far north, sunrise usually happens at around 05:00 (DST) and the sun sets at around 21:00 (DST)...that means that you could go for an evening stroll while it's completely lighted. I'm sure there are some calculators around that allow you to calculate sunrise and sunset given latitude and longitude... User:KeithH 07:28, 25 Mar 2005 (UTC) :The big advantage of DST is that it "transfers" an hour or so from early in the day when few people are up and about to the evening, when activity is high. In effect there is a "free" hour of sunlight, with consequent savings in electicity usage. During WW2 the UK experienced double DST, when the clocks were advanced two hours rather than one, to take advantage of the very long hours of sunlight in high summer. Personally, I enjoy the long summer evenings, and it is pleasant to take a stroll or have a relaxing drink outside at that time of year, using time that would otherwise be dark. A disadvantage for parents of small children is that it can be harder to get them to sleep while the sun is still quite high in the sky. User:Skyring 08:55, 23 May 2005 (UTC) == I challenge a statement made in the main article == 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. … This would make winter evenings longer, thereby reducing traffic accidents and cases of seasonal affective disorder. It wouldn't necessarily reduce SAD. I suffer from it, and for me the biggest problem is the darkness in the morning. Many SAD sufferers, including myself, need the dawn to tell our bodies that it is time to wake up and hence have difficulty waking up during the winter. We can also have difficulty staying awake during the day as, even though we may have had eight hours as recommended, our bodies are still convinced that we were woken up in the middle of the night. Granted, the above problems can be worked around with a dawn simulator, but that does not excuse adopting a time system that would trigger new cases of SAD and/or worsen existing ones. The existence of a treatment for any given illness does not make it ethically acceptable to adopt an avoidable practise which will trigger that illness, and SAD is no exception.
Melatonin is produced as it gets dark, making us feel sleepy. At dawn, as the light increases, melatonin production falls and we start to wake up. We find it difficult to wake up on dark mornings because our melatonin levels are still high.From: http://www.lumie.com/sad.htm Other information: http://www.solar-components.com/dawnsim.htm ---- (Please sign your posts on Talk pages using "
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