Daylight saving time (DST) is the practice of advancing clocks
during the lighter months so that evenings have more daylight and mornings have
less. Typically clocks are adjusted forward one hour near the start of spring
and are adjusted backward in autumn.
The modern idea of daylight saving was first proposed in 1895
by George Vernon Hudson and it was first implemented during the First World
War. Many countries have used it at various times since then. Much of the
United States used DST in the 1950s and 1960s, and DST use expanded following
the 1970s energy crisis and has been widely used in North America and Europe
since then.
The practice has been both praised and criticized. Adding
daylight to evenings benefits retailing, sports, and other activities that
exploit sunlight after working hours, but can cause problems for evening
entertainment and other occupations tied to the sun. Although an early goal of
DST was to reduce evening usage of incandescent lighting (formerly a primary
use of electricity), modern heating and cooling usage patterns differ greatly,
and research about how DST currently affects energy use is limited or
contradictory.
DST clock shifts present other challenges. They complicate
timekeeping, and can disrupt meetings, travel, billing, record keeping, medical
devices, heavy equipment, and sleep patterns. Software can often adjust
computer clocks automatically, but this can be limited and error-prone,
particularly when DST dates are changed.
As of now every electronic device programmed as such the time changes according to DST.
Most countries that observe Daylight Saving Time are listed
Continent | Country | Beginning and ending days |
Africa | Egypt | Start: Last Friday in April End: Last Thursday in September |
Namibia | Start: First Sunday in September End: First Sunday in April | |
Tunisia | In 2009 the government of Tunisia canceled DST and kept the standard time all year round. | |
Asia | Most states of the former USSR. | Start: Last Sunday in March End: Last Sunday in October |
Bangladesh | Cancelled in 2010. | |
Iraq | Start: First Friday in April End: Last Friday in October | |
Israel | Start: Last Friday before April 2 End: The Sunday between Rosh Hashana and Yom Kippur | |
Jordan | Start: Last Thursday of March End: Last Friday in September | |
Lebanon, Kyrgyzstan | Start: Last Sunday in March End: Last Sunday in October | |
Mongolia | Start: Fourth Friday in March End: Last Friday in September | |
Palestinian regions | (Estimate) Start: First Friday on or after 15 April End: First Friday on or after 15 October | |
Syria | Start: March 30 End: September 21 | |
Australasia | Australia - South Australia, Victoria, Australian Capital Territory, New South Wales, Lord Howe Island | Start: First Sunday in October End: First Sunday in April |
Australia - Tasmania | Start: First Sunday in October End: Last Sunday in March | |
Fiji | Stopped in 2000 | |
New Zealand, Chatham
| Start: Last Sunday in September End: First Sunday in April | |
Tonga | Start: First Sunday in November End: Last Sunday in January | |
Europe | European Union UK | Start: Last Sunday in March at 1 am UTC End: Last Sunday in October at 1 am UTC |
Russia | Permanent, as of February 2011 | |
North America | United States, Canada (excluding Saskatchewan and parts of Quebec, B.C., and Ontario), Bermuda, St. Johns, Bahamas, Turks and Caicos | Start: Second Sunday in March End: First Sunday in November |
Cuba | Start: Third Sunday in March End: Last Sunday of October. | |
Greenland | Same as EU | |
Honduras | Start: May 7 End: August | |
Mexico (except Sonora) | Start: First Sunday in April End: Last Sunday in October | |
South America | Argentina. Started Sun Dec 30, 2007 Ending 16 March 2008. Practiced in 2009. | Not currently observed. |
Brazil Equatorial Brazil does not observe DST. | Start: Third Sunday in October End: Third Sunday in February | |
Chile | Start:October 11 End: March 29 | |
Falklands | Start: First Sunday on or after 8 September End: First Sunday on or after 6 April | |
Paraguay | Start: Third Sunday in October End: Second Sunday in March | |
Uruguay | Start: First Sunday in October End: Second Sunday in March |