Daylight saving time in the Americas
Daylight saving time in the Americas is the arrangement in the Americas by which clocks are advanced by one hour in spring and moved back in autumn, to make the most of seasonal daylight. The practice is widespread in North America, with most of Canada, Mexico and the United States participating, but much less so in South America.
- 1 North America
- 2 South America
- 3 See also
- 4 References
Canada, Mexico and the United States
Canada, Mexico and the United States use Daylight saving time on a wide scale, with only a few states/provinces and parts thereof opting out of the practice or adopting it year-round without the twice yearly switch.
The United States territory of Puerto Rico adopted DST through legislation passed in 2000 but, after a change in governors, dropped it in 2001, three days before it would have gone into effect.
Since 2007, in areas of Canada and United States in which it is used, daylight saving time begins on the second Sunday of March and ends on the first Sunday of November. Border cities in Mexico also follow this pattern, while the remainder of Mexico begins on the first Sunday of April, and ends last Sunday of October.
Saint Pierre and Miquelon
Saint Pierre and Miquelon, located near the Canadian coast, belongs to France, but observes daylight saving time according to Canadian rules.
Greenland (excluding two minor areas at Danmarkshavn and Pituffik) observes DST and uses the European convention (DST begins 01:00 UTC last Sunday in March and ends 01:00 UTC last Sunday in October). Most populated places in the country are in the UTC-3 zone in the winter (UTC-2 in the summer). Because of this, with respect to local time, clocks are changed from 22:00 to 23:00 in the spring (on the Saturday before the last Sunday in March), and reset back from 23:00 to 22:00 in the autumn (on the Saturday before the last Sunday in October). Pituffik/Thule Air Base uses UTC-4 and United States conventions on DST because it is a US air base, meaning it is part of the Atlantic Time Zone.
The Commonwealth of The Bahamas observes DST according to the American schedule. Although not part of the Caribbean geographically, it is often included in the Caribbean in regional interactions and shares much of its culture with its southern neighbors.
Barbados in the western Atlantic no longer observes Daylight Saving Time, like many Caribbean nations. The last observance of a daylight savings related time clock adjustment was between Sunday, 20 April 1980 at 2:00 AM – Thursday, 25 September 1980 at 2:00 AM. On 25 September the clock was shifted -3:00 – -4:00 where it has remained since.
Cuba normally observes DST from March to October although the precise dates vary. For two years in the mid-2000s (decade), Cuba stayed on DST throughout the year. In 2009 it was on DST from the second Sunday in March to the last Sunday of October. In 2011, it was on DST from the third Sunday in March to the second Sunday in November.
Dominica in the Caribbean does not observe Daylight Saving Time, like several other Caribbean nations.
Haiti reestablished Daylight Saving Time again in 2012, following the US/Canada DST Rules, starting on second Sunday in March and ending on first Sunday in November.
Jamaica previously used Daylight Saving Time, utilising the US and Canadian rules. The practise was used from 1974 before being discontinued in 1983.
Guatemala has used DST during energy crises. The last time it used DST was on April 30, 2006, ending on October 1, 2006. However DST was not observed in 2007-09.
Honduras adopted DST once, from May 1994 until September 1994 but then abandoned it. On May 7, 2006 it again used DST; however it ended on August 7, 2006, making this the shortest use of DST in the northern hemisphere as it was only applied for 3 months. The government decided not to use DST in 2007.
Nicaragua observed DST from January 1, 1992 until February 20, 1994 but it was stopped. On April 10, 2005 until October 2, 2005 DST was implemented, and the following year the period was similar, beginning on April 30, 2006 and ending on October 1, 2006; this measure was for energy conservation. In 2007, the government of Nicaragua decided to stop observing daylight saving time.
In equatorial regions, the use of DST is not useful because of the stability of light levels throughout the year. As a result large areas of South America do not use DST. DST is used in some of the more southerly countries such as Chile, Paraguay, Uruguay, and in some Brazilian states.
These countries or regions in South America do not use daylight saving time:
- French Guiana
- The following states of Brazil: Acre, Alagoas, Amapá, Amazonas, Bahia, Ceará, Maranhão, Pará, Paraíba, Pernambuco, Piauí, Rio Grande do Norte, Rondônia, Roraima, Sergipe, and Tocantins.
Since 2009, Argentina is not observing DST and the entire country stays on UTC-3.
San Luis province, which was previously in a different time zone than most of the country and which formerly observed DST, decided in April 2010 not to change its clocks back and to stay on UTC-3 all year round.
The most recent history of Argentina observing DST dates from 2007 to 2009. After a period of not observing DST, Argentina observed DST in some provinces in an attempt to save energy. For each period, the executive branch of the government set the specific start and end dates for DST, i.e. there was no fixed annual schedule.
In 2011, Bolivia planned to observe DST starting September 1 for the first time in its history, advancing the clock an hour on a nationwide basis in order to offset their energy problems. The schedule change was planned to take place every year between September and March, corresponding to the spring and summer of the South American country. However, the day before the scheduled change, on August 31, 2011, the national government indefinitely suspended the observation of DST due to opposition from experts in electricity, neighborhood and school leaders, and the general populace.
Brazil adopted DST (called horário de verão—"summer time"—in Portuguese) for the first time in 1931, and it was in effect across the entire country. The duration and regional applicability of DST has varied over the years (see Portuguese Wikipedia page for details). As of 2011, DST is used only in the southern region (the states of Rio Grande do Sul, Santa Catarina, Paraná), the southeast region (the states of São Paulo, Rio de Janeiro, Espirito Santo, Minas Gerais), the central-west region (the state of Goiás and the Distrito Federal, and the states of Mato Grosso and Mato Grosso do Sul), and in Bahia.
Formerly, starting and ending dates were variable, but in 2008, a decree (No. 6558 of 9 September 2008) established a permanent rule: DST starts at 00:00 on the third Sunday in October and ends at 00:00 on the third Sunday in February—unless the latter falls during Carnaval: in this case, the end of DST is postponed by one week. The next five times in which the end of DST is scheduled to be postponed are 2015, 2023, 2026, 2034 and 2037.
Chile observes DST from the second Saturday in October to the second Saturday in March, but it may vary (see Time in Chile). In 2008, for example, the time was adjusted on Sunday, March 30, at 12 midnight. In 2010, because of the Earthquake, DST remained in effect until April 3. In 2011, in order to prevent energy shortages after a dry summer, DST was first extended until April 2  and then until May 7. Starting 2011, Chilean DST starts the first Saturday of September at 24:00, and ends the last Saturday of April at 24:00.
From February 1992 until March 1993, Colombia suffered rolling blackouts of up to 10 hours a day due to a particularly strong El Niño season, which dried the reservoirs in hydroelectric plants in a country deriving 70% of its energy output from hydroelectric sources; consequently, the government decided to use DST to help save electricity. The experiment failed to deliver the intended results, possibly due to Colombia's low latitude, and the DST experiment was discontinued.
President Sixto Durán Ballén imposed daylight saving time in 1992 in an energy-saving effort. It was poorly received by the populace and did not last long.
Paraguay observes DST under decree 1867 of March 5, 2004. DST ends on the second Sunday of March and starts on the third Sunday of October.
In 2007, DST started on October 15, 2006 and ended on March 11, 2007.
In 2010, Paraguay changed its own DST rules because of the energy crisis, ending DST on the second Sunday in April, a month later than previous years. The start date remains unchanged.
- "Regirá el horario de verano desde el próximo domingo 16 de marzo". Granma.cubaweb.cu. Archived from the original on June 22, 2008. Retrieved 2010-06-25.
- "Regirá horario de verano desde el próximo domingo 13". Granma.cubaweb.cu. Retrieved 2011-11-13.
- "Time zone in Guatemala". Time and Date.com. Retrieved 2009-05-24.
- "Gobierno recapacita y suspende adelanto de hora". La Prensa (in Spanish). 2007-03-30.
- Desde el 1 de septiembre de 2011, los relojes de los bolivianos deberán ser modificados, en una hora. (in spanish)
- Bolivia adelantará la hora por primera vez en septiembre de 2011 (in spanish)
- Se posterga cambio de huso horario en Bolivia (in spanish)
- "DST Spread in Chile By the Earthquake (In Spanish)". Microsoft.com. Retrieved 2010-06-25.
- "Decreto 163 (In Spanish)". 2011-03-03. Retrieved 2011-04-14.
- "Decreto 200 (In Spanish)". 2011-03-28. Retrieved 2011-04-14.
- "Time zone changes and daylight saving time start/end dates between year 1990 and 1999 - Bogota, Colombia". timeanddate.com. Retrieved 2008-05-09.
- "Time zone and daylight saving time for the Falkland Islands - Stanley between 2000 and 2009". Timeanddate.com. Retrieved 2010-06-25.
- "Mercopress article - Falkland Islands will remain on summer time throughout 2011". Mercopress. Retrieved 2011-04-01.
- Time zone in Stanley
- Decreto 1303/06 - Presidencia de la República Oriental del Uruguay