Daylight saving time (DST) or summer time is the practice of advancing clocks during the summer months that have more sunlight so that people get up later in the morning and go to bed later at night. Typically clocks are adjusted forward one hour near the start of spring and are adjusted backward in the autumn.
The modern idea of daylight saving was first proposed in 1895 by George Vernon Hudson, and it was first implemented by Germany and Austria-Hungary starting on 30 April 1916. Many countries have used it at various times since then, most consistently since the energy crisis of the 1970s.
The practice has been both advocated and criticized. Putting clocks back benefits retailing, sports, and other activities that exploit sunlight after working hours, but can cause problems for evening entertainment and other activities tied to the sun (such as farming) or to darkness (such as firework shows). Although an early goal of DST was to reduce evening use 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.
Other problems sometimes caused by DST clock shifts are: 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.
| Country/Territory | Continent | Summer/Hemisphere | DST start (adjust clocks forward) |
DST end (adjust clocks backward) |
Notes and other mentions |
|---|---|---|---|---|---|
| Afghanistan | Asia | – | – | – | Does not use DST |
| Akrotiri and Dhekelia(UK) | Europe | Boreal/North | Last Sunday March | Last Sunday October | |
| Albania | Europe | Boreal/North | Last Sunday March | Last Sunday October | Observed DST in 1940-1943, and since 1974. |
| Algeria | Africa | – | – | – | Observed DST in 1916-1921, in the autumn of 1939, in 1944-1945, 1971, 1977-1978 and 1980-1981 . |
| American Samoa (US) | Oceania | – | – | – | Does not use DST |
| Andorra | Europe | Boreal/North | Last Sunday March | Last Sunday October | Observed DST since 1985. |
| Angola | Africa | – | – | – | Does not use DST |
| Anguilla (UK) | Central America | – | – | – | Does not use DST |
| Antigua and Barbuda | Central America | – | – | – | Does not use DST |
| Argentina | South America | – | – | – | Observed DST in 1930-1969, 1974, 1988-2000, 2007-2009. |
| Armenia | Europe | – | – | – | Observed DST in 1981-1995, 1997-2011. |
| Aruba (NL) | Central America | – | – | – | Does not use DST |
| Australia | Oceania | Austral/South | First Sunday October | First Sunday April |
Main article: Daylight saving time in Australia
DST used only in Australian Capital Territory,Victoria, New South Wales, Tasmania, South Australia and Lord Howe Island. |
| Austria | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916-1918, 1920, 1940-1948 and since 1980. |
| Azerbaijan | Europe | Boreal/North | Last Sunday March | Last Sunday October | Observed DST in 1981-1992 and since 1996.Nagorno-Karabakh abolished DST in 2012. |
| Bahamas | North America | Boreal/North | Second Sunday March | First Sunday November | Observed DST since 1964. |
| Bahrain | Asia | – | – | – | Does not use DST |
| Bangladesh | Asia | – | – | – | Observed DST in 2009. |
| Barbados | Central America | – | – | – | Observed DST from 1977-1980. |
| Belarus | Europe | – | – | – | Observed DST in 1941-1944, 1981-2010. |
| Belgium | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916-1940, 1942-1946 and since 1977. |
| Belize | Central America | – | – | – | Observed DST in 1973-1974 and 1982-1983. |
| Benin | Africa | – | – | – | Does not use DST |
| Bermuda (UK) | North America | Boreal/North | Second Sunday March | First Sunday November | Observed DST since 1974. |
| Bhutan | Asia | – | – | – | Does not use DST |
| Bolivia | South America | – | – | – | Observed DST in 1931-1932. |
| Bonaire (NL) | Central America | – | – | – | Does not use DST |
| Bosnia and Herzegovina | Europe | Boreal/North | Last Sunday March | Last Sunday October | Observed DST in 1941-1945 and since 1983. |
| Botswana | Africa | – | – | – | Observed DST in 1943-1944. |
| Brazil | South America | Austral/South | Third Sunday October | Third Sunday February |
Main article: Daylight saving time in Brazil
DST end delays one week during Carnival week. Only these south and central states use DST: São Paulo, Rio de Janeiro, Federal District Brasilia,Santa Catarina, Paraná, Goiás, Rio Grande do Sul,Mato Grosso do Sul, Espírito Santo, Minas Geraisand Mato Grosso (some exceptions). |
| British Virgin Islands(UK) | Central America | – | – | – | Does not use DST |
| Brunei | Asia | – | – | – | Does not use DST |
| Bulgaria | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1943-1944 and since 1979. |
| Burkina Faso | Africa | – | – | – | Does not use DST |
| Burma | Asia | – | – | – | Does not use DST |
| Burundi | Africa | – | – | – | Does not use DST |
| Cambodia | Asia | – | – | – | Does not use DST |
| Cameroon | Africa | – | – | – | Does not use DST |
| Canada | North America | Boreal/North | Second Sunday March | First Sunday November |
Main article: Daylight saving time in Canada
Some regions in Quebec, east of 63° westlongitude, most of Saskatchewan, Southampton Island and some areas in British Columbia do not observe DST. Saskatchewan however, observes Central Time even though it is located in the Mountain Time Zone, meaning it effectively observes DST year round. |
| Cape Verde | Africa | – | – | – | Observed DST in 1942-1945. |
| Cayman Islands (UK) | Central America | – | – | – | Does not use DST |
| Central African Republic | Africa | – | – | – | Does not use DST |
| Chad | Africa | – | – | – | Observed DST in winter 1979-1980. |
| Chile | South America | Austral/South | Second Sunday September | Last Sunday April | Observed DST in 1927-1946 (excluding Easter Island which observed it in 1932-1946 ) and since 1968. Easter Island starts on Saturday to sync withChile |
| China | Asia | – | – | – | Observed DST in 1986-1991. |
| Christmas Island (AU) | Asia | – | – | – | Does not use DST |
| Cocos Island (AU) | Asia | – | – | – | Does not use DST |
| Colombia | South America | – | – | – | Observed DST in 1992-1993. |
| Comoros | Africa | – | – | – | Does not use DST |
| Congo | Africa | – | – | – | Does not use DST |
| Cook Islands (NZ) | Oceania | – | – | – | Observed DST in 1978-1991. |
| Costa Rica | Central America | – | – | – | Observed DST in 1954, 1979-1980 and 1991-1992. |
| Croatia | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1941-1945 and since 1983. |
| Cuba | Central America | Boreal/North | Second Sunday March | First Sunday November | Observed DST in 1928, 1940-1942, 1945-1946 and since 1965. |
| Curacao (NL) | Central America | – | – | – | Does not use DST |
| Cyprus | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST since 1975. |
| Czech Republic | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916-1918, 1940-1949 and since 1979. |
| Democratic Republic of Congo | Africa | – | – | – | Does not use DST |
| Denmark | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916, 1940-1948 and since 1980. |
| Djibouti | Africa | – | – | – | Does not use DST |
| Dominica | Central America | – | – | – | Does not use DST |
| Dominican Republic | Central America | – | – | – | Observed DST in 1966-1967, 1969-1974. |
| East Timor | Asia | – | – | – | Does not use DST |
| Ecuador | South America | – | – | – | Does not use DST |
| Egypt | Africa/Asia | Boreal/North | Last Friday April | Last Friday September | Observed DST in 1940-1945 and 1957-2010. Re-introduces DST in 2014. DST is stopped during Ramadan |
| El Salvador | Central America | – | – | – | Observed DST in 1987-1988. |
| Equatorial Guinea | Africa | – | – | – | Does not use DST |
| Eritrea | Africa | – | – | – | Does not use DST |
| Estonia | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1918, 1940-1944 and since 1981. |
| Ethiopia | Africa | – | – | – | Does not use DST |
| Falkland Islands (UK) | South America | – | – | – | Keeps on continuous DST since 2011 |
| Faroe Islands (DK) | Europe | Boreal/North | Last Sunday March | Last Sunday October | Observed DST since 1981. |
| Fiji | Oceania | Austral/South | Last Sunday October | Third Sunday January | Observed DST in 1998-2000 and since 2009. |
| Finland | Europe | Boreal/North | Last Sunday March | Last Sunday October | Observed DST in 1942 and since 1981. |
| France | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916-1945 and since 1976. |
| French Guyana (FR) | South America | – | – | – | Does not use DST |
| French Polynesia (FR) | Oceania | – | – | – | Does not use DST |
| French Southern and Antarctic Lands (FR) | Antarctica | – | – | – | Does not use DST |
| Gabon | Africa | – | – | – | Does not use DST |
| Gambia | Africa | – | – | – | Does not use DST |
| Georgia | Europe | – | – | – | Observed DST in 1981-2005. |
| Germany | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916-1918, 1940-1949, and since 1980. |
| Ghana | Africa | – | – | – | Observed DST from 1936-1942. |
| Greece | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916-1968 and since 1971. |
| Greenland | North America | Boreal/North | 22:00 local time on Saturday before last Sunday March | 23:00 local time on Saturday before last Sunday October | Observed DST since 1980.Follows European Union practice, although not a member: hence start & end times correspond to 01:00 UTC on the respective Sunday. See Daylight saving time in the Americas—Greenland Qaanaaquses US and Canada rules. Danmarkshavn does not use DST. |
| Grenada | Central America | – | – | – | Does not use DST |
| Guadeloupe (FR) | Central America | – | – | – | Does not use DST |
| Guam (US) | Oceania | – | – | – | Does not use DST |
| Guatemala | Central America | – | – | – | Observed DST in 1973-1974, 1983, 1991 and 2006. |
| Guernsey (UK) | Europe | Boreal/North | 01:00 GMT on last Sunday March | 01:00 GMT on last Sunday October | Observed DST in 1916-1968 and since 1972. |
| Guinea | Africa | – | – | – | Does not use DST |
| Guinea-Bissau | Africa | – | – | – | Does not use DST |
| Guyana | South America | – | – | – | Does not use DST |
| Haiti | Central America | Boreal/North | Second Sunday March | First Sunday November | Observed DST in 1983-1997, 2005-2006 and from 2012 onwards. |
| Heard and McDonald Islands (AU) | Antarctica | – | – | – | Does not use DST |
| Holy See | Europe | Boreal/North | Last Sunday March | Last Sunday October | Observed DST in 1916-1920, 1940-1948 and since 1966. |
| Honduras | Central America | – | – | – | Observed DST in 1987-1988 and 2006 . |
| Hong Kong | Asia | – | – | – | Observed DST in 1941, 1945-1976 and 1979. |
| Hungary | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916-1920, 1941-1950, 1954-1957 and since 1980. |
| Iceland | Europe | – | – | – | Observed DST in 1917-1918 and 1939-1968. |
| India | Asia | – | – | – | Observed DST in 1942-1945. |
| Indonesia | Asia | – | – | – | Does not use DST |
| Iran | Asia | Boreal/North | March 21–22 | September 21–22 | Observed DST in 1977-1980, 1991-2005 and since 2008. |
| Iraq | Asia | – | – | – | Observed DST in 1982-2007. |
| Ireland | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916-1968 and since 1972. |
| Isle of Man (UK) | Europe | Boreal/North | 01:00 GMT on last Sunday March | 01:00 GMT on last Sunday October | Observed DST in 1916-1968 and since 1972. |
| Israel | Asia | Boreal/North | Friday before last Sunday March | Last Sunday October | Observed DST in 1940-1946, 1948-1957, 1974-1975 and since 1985. |
| Italy | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916-1920, 1940-1948 and since 1966. |
| Ivory Coast | Africa | – | – | – | Does not use DST |
| Jamaica | Central America | – | – | – | Observed DST in 1974-1983. |
| Japan | Asia | – | – | – | Observed DST in 1948-1951. |
| Jersey (UK) | Europe | Boreal/North | 01:00 GMT on last Sunday March | 01:00 GMT on last Sunday October | Observed DST in 1916-1968 and since 1971. |
| Jordan | Asia | Boreal/North | Last Friday March | Last Friday October | Returned again to UTC+2 on Dec, 20 2013, Previsible with DST |
| Kazakhstan | Asia | – | – | – | Observed DST in 1981-1990 and 1992-2004. |
| Kenya | Africa | – | – | – | Does not use DST |
| Kiribati | Oceania | – | – | Does not use DST | |
| Kosovo | Europe | Boreal/North | Last Sunday March | Last Sunday October | Observed DST since 1983. |
| Kuwait | Asia | – | – | – | Does not use DST |
| Kyrgyzistan | Asia | – | – | – | Observed DST in 1981-2005. |
| Laos | Asia | – | – | – | Does not use DST |
| Latvia | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1918-1919, 1941-1944 and since 1981. |
| Lebanon | Asia | Boreal/North | Last Sunday March | Last Sunday October | Observed DST in 1920-1923, 1957-1961, 1972-1978 and since 1984. |
| Lesotho | Africa | – | – | – | Observed DST in 1943-1944. |
| Liberia | Africa | – | – | – | Does not use DST |
| Libya | Africa | – | – | – | Observed DST in 1951, 1955, 1957, 1982-1989,1997.and 2013. |
| Liechtenstein | Europe | Boreal/North | Last Sunday March | Last Sunday October | Observed DST since 1981. |
| Lithuania | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1941-1944, 1981-1999 and since 2003. |
| Luxembourg | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916-1946 and since 1977. |
| Macao (CH) | Asia | – | – | – | Observed DST in 1961-1980. |
| Macedonia | Europe | Boreal/North | Last Sunday March | Last Sunday October | Observed DST in 1941-1945 and since 1983. |
| Madagascar | Africa | – | – | – | Observed DST in 1954. |
| Malawi | Africa | – | – | – | Does not use DST |
| Malaysia | Asia | – | – | – | Observed DST in 1933-1935. |
| Maldives | Asia | – | – | – | Does not use DST |
| Mali | Africa | – | – | – | Does not use DST |
| Malta | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916-1920, 1940-1948 and since 1966. |
| Marshall Islands | Oceania | – | – | – | Does not use DST |
| Martinica (FR) | Central America | – | – | – | Observed DST in 1980. |
| Mauritania | Africa | – | – | – | Does not use DST |
| Mauritius | Africa | – | – | – | Observed DST in 1982-1983 and 2008-2009. |
| Mexico | North America | Boreal/North | First Sunday April | Last Sunday October | Observe DST since 1996, but Baja Californiaobserve DST since 1942. Sonora observed DST 1996–1997. Locations less than 20 km from the US border use US DST. |
| Micronesia | Oceania | – | – | – | Does not use DST |
| Midway (US) | Oceania | – | – | – | Observed DST in 1956. |
| Moldova | Europe | Boreal/North | Last Sunday March | Last Sunday October | Observed DST in 1932-1944, 1981-1989 and since 1991. |
| Monaco | Europe | Boreal/North | Last Sunday March | Last Sunday October | Observed DST in 1916-1945 and since 1976. |
| Mongolia | Asia | – | – | – | Observed DST in 1983-1998 and 2001-2006. |
| Montenegro | Europe | Boreal/North | Last Sunday March | Last Sunday October | Observed DST 1941-1945 and since 1983. |
| Montserrat (UK) | Central America | – | – | – | Does not use DST |
| Morocco | Africa | Boreal/North | Last Sunday March | Last Sunday October | Observed DST in 1939-1945, 1950, 1967, 1974, 1974-1976 and since 2008. DST stops during Ramadan. |
| Mozambique | Africa | – | – | – | Does not use DST |
| Namibia | Africa | Austral/South | First Sunday September | First Sunday April | Observed DST in 1942-1943 and since 1994. |
| Nauru | Oceania | – | – | – | Does not use DST |
| Nepal | Asia | – | – | – | Does not use DST |
| Netherlands | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916-1945 and since 1977. |
| New Caledonia (FR) | Oceania | – | – | – | Observed DST in 1977-1979 and 1996-1997. |
| New Zealand | Oceania | Austral/South | Last Sunday September | First Sunday April | Observed DST in 1927-1946 and since 1974. |
| Nicaragua | Central America | – | – | – | Observed DST in 1973-1975, 1979-1980, 1992-1994 and 2005-2006. |
| Niger | Africa | – | – | – | Does not use DST |
| Nigeria | Africa | – | – | – | Does not use DST |
| Niue (NZ) | Oceania | – | – | – | Does not use DST |
| North Korea | Asia | – | – | – | Does not use DST |
| Northern Mariana Islands (US) | Oceania | – | – | – | Does not use DST |
| Norway | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916, 1940-1945, 1959-1965 and since 1980.Follows European Union practice, although not a member. |
| Oman | Asia | – | – | – | Does not use DST |
| Pakistan | Asia | – | – | – | Observed DST in 1942-1945 (as belonging to India) and 2002. |
| Palau | Oceania | – | – | – | Does not use DST |
| Palestine | Asia | Boreal/North | Last Friday March | Last Friday September | Observed DST in 1940-1946, 1957-1967, 1974-1975 and since 1985. |
| Panama | Central America | – | – | – | Does not use DST |
| Papua New Guinea | Oceania | – | – | – | Does not use DST |
| Paraguay | South America | Austral/South | First Sunday October | Fourth Sunday March | Observed DST since 1975. Current start and end dates last updated in 2013. |
| Peru | South America | – | – | – | Observed DST in 1938-1940, 1986-1987, 1990 and 1994. |
| Philippines | Asia | – | – | – | Observed DST in 1936-1937, 1954, 1978 and 1990. |
| Pitcairn Islands (UK) | Oceania | – | – | – | Does not use DST |
| Poland | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916-1919, 1940-1949, 1957-1964 and since 1977. |
| Portugal | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916-1921, 1924, 1926-1929, 1931-1932, 1934-1949, 1951-1965 and since 1977. |
| Puerto Rico (US) | Central America | – | – | – | Observed DST in 1942-1945. |
| Qatar | Asia | – | – | – | Does not use DST |
| Romania | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1932-1939 and since 1979. |
| Russia | Asia/Europe | – | – | – | Observed DST in 1917-1919 and 1921 (some areas), 1981-2010 . Since 2011 abolishes DST. |
| Rwanda | Africa | – | – | – | Does not use DST |
| Saba (NL) | Central America | – | – | – | Does not use DST |
| Saint Barthélemy (FR) | Central America | – | – | – | Does not use DST |
| Saint Helena, Ascension and Tristan da Cunha (UK) | Africa/South America | – | – | – | Does not use DST |
| Saint Kitts and Nevis | Central America | – | – | – | Does not use DST |
| Saint Lucia | Central America | – | – | – | Does not use DST |
| Saint Martin (FR) | Central America | – | – | – | Does not use DST |
| Saint Pierre and Miquelon (FR) | North America | Boreal/North | Second Sunday March | First Sunday November | Observed DST since 1987. |
| Saint Vincent and the Grenadines | Central America | – | – | – | Does not use DST |
| Samoa | Oceania | Austral/South | Last Sunday September | First Sunday April | Observed DST since 2011 |
| San Marino | Europe | Boreal/North | Last Sunday March | Last Sunday October | Observed DST in 1916-1920, 1940-1948 and since 1966. |
| Sao Tome and Príncipe | Africa | – | – | – | Does not use DST |
| Saudi Arabia | Asia | – | – | – | Does not use DST |
| Senegal | Africa | – | – | – | Does not use DST |
| Serbia | Europe | Boreal/North | Last Sunday March | Last Sunday October | Observed DST in 1941-1945 and since 1983. |
| Seychelles | Africa | – | – | – | Does not use DST |
| Sierra Leone | Africa | – | – | – | Observed DST in 1935-1942 and 1957-1962. |
| Singapore | Asia | – | – | – | Observed DST in 1933-1935 by adding 20 minutes to standard time. On January 1, 1936, country changed their time zone to UTC+7:20. |
| Sint Eustatius (NL) | Central America | – | – | – | Does not use DST |
| Sint Maarten (NL) | Central America | – | – | – | Does not use DST |
| Slovakia | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916-1918, 1940-1949 and since 1979. |
| Slovenia | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1941-1945 and since 1983. |
| Solomon Islands | Oceania | – | – | – | Does not use DST |
| Somalia | Africa | – | – | – | Does not use DST |
| South Africa | Africa | – | – | – | Observed DST in 1942-1944. |
| South Georgia Islands(UK) | Antarctica | – | – | – | Does not use DST |
| South Korea | Asia | – | – | – | Observed DST in 1948-1951, 1955-1960 and 1987-1988. |
| South Sandwich Islands (UK) | Antarctica | – | – | – | Does not use DST |
| South Sudan | Africa | – | – | – | Observed DST in 1970-1985. |
| Spain | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1917-1919, 1924, 1926-1929, 1937-1946, 1949 and since 1974. On Canary Islands DST observed since 1980. |
| Sri Lanka | Asia | – | – | – | Observed DST in 1942-1945. |
| Sudan | Africa | – | – | – | Observed DST in 1970-1985. |
| Suriname | South America | – | – | – | Does not use DST |
| Swaziland | Africa | – | – | – | Does not use DST |
| Sweden | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST 15 May–30 September 1916, and since the first Sunday of April in 1980. Before 1996 it ended on the last Sunday of September. |
| Switzerland | Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1941-1942 and since 1980.Follows European Union practice, although not a member. |
| Syria | Asia | Boreal/North | Last Friday March | Last Friday October | Observed DST in 1920-1923, 1962-1968 and since 1983. |
| Taiwan | Asia | – | – | – | Observed DST in 1945-1962, 1974, 1975 and 1979. |
| Tajikistan | Asia | – | – | – | Observed DST in 1981-1991. |
| Tanzania | Africa | – | – | – | Does not use DST |
| Thailand | Asia | – | – | – | Does not use DST |
| Togo | Africa | – | – | – | Does not use DST |
| Tokelau (NZ) | Oceania | – | – | – | Does not use DST |
| Tonga | Oceania | – | – | – | Observed DST from 1999-2002. |
| Trinidad and Tobago | Central America | – | – | – | Does not use DST |
| Tunisia | Africa | – | – | – | Observed DST in 1939-1945, 1977-1978, 1988-1990 and 2005-2008. |
| Turkey | Asia/Europe | Boreal/North | 01:00 UTC on last Sunday March | 01:00 UTC on last Sunday October | Observed DST in 1916, 1920-1922, 1924-1925, 1940-1942, 1945-1951, 1962, 1964, 1970-1983 and since 1985.Follows European Union practice, although not a member. |
| Turkmenistan | Asia | – | – | – | Observed DST in 1981-1991. |
| Turks and Caicos (UK) | Central America | Boreal/North | Second Sunday March | First Sunday November | Observed DST since 1979. |
| Tuvalu | Oceania | – | – | – | Does not use DST |
| Uganda | Africa | – | – | – | Does not use DST |
| Ukraine | Europe | Boreal/North | Last Sunday March | Last Sunday October | Observed DST in 1941-1943, 1981-1989 and since 1992.The Crimean Supreme Council announced thatCrimea will switch to Moscow time (which does not observe DST) in March 2014 . |
| United Arab Emirates | Asia | – | – | – | Does not use DST |
| United Kingdom | Europe | Boreal/North | 01:00 GMT on last Sunday March | 01:00 GMT on last Sunday October |
Main article: British Summer Time
Observed DST (British Summer Time (BST)) since 1916.Year-round Summer Time (BST) + Double Summer Time (BDST) 1940-1945. Two-stage Double Summer Time (BDST) 1947. Year-round Summer Time (BST) 1968-1971. |
| United States | North America | Boreal/North | Second Sunday March | First Sunday November |
Main article: Daylight saving time in the United States
Arizona (except the Navajo Nation Community) and Hawaii do not use DST.[10] |
| United States Virgin Islands (US) | Central America | – | – | – | Does not use DST |
| Uruguay | South America | Austral/South | First Sunday October | Second Sunday March | Observed DST in 1923-1926, 1933-1943, 1959-1960, 1965-1970, 1972, 1974-1980, 1987-1993 and since 2004. |
| Uzbekistan | Asia | – | – | – | Observed DST in 1981-1991. |
| Vanuatu | Oceania | – | – | – | Observed DST in 1983-1993. |
| Venezuela | South America | – | – | – | Does not use DST |
| Vietnam | Asia | – | – | – | Does not use DST |
| Wallis and Futuna(FR) | Oceania | – | – | – | Does not use DST |
| Western Sahara | Africa | Boreal/North | Last Sunday March | Last Sunday October | Observed DST since 2008. DST is stopped during Ramadan. Only areas controlled by Morocco uses DST. |
| Yemen | Asia | – | – | – | Does not use DST |
| Zambia | Africa | – | – | – | Does not use DST |
| Zimbabwe | Africa | – | – | – | Does not use DST |
Courtesy : CGP Grey via Youtube and Wikipedia
