Like it or not, this year’s Daylight Saving Time (DST) begins in the United States at 2 a.m. on March 12, which means either losing an hour of sleep or lingering in bed later than usual on Sunday morning as the nation’s clocks “spring forward” by an hour to gain early evening sunlight until early November.
The reason for the twice-annual time change is ostensibly to save energy that would be spent consuming electricity for lighting. According to Scientific American, Benjamin Franklin first proposed the idea in 1784 to conserve candles. The U.S. implemented DST during both world wars to help preserve electricity. The time charge was codified federally during the oil crisis of the early 1970s.
But many argue the change is superficial and may actually lead to more energy consumption as households consume more electricity to cool their homes in the evening. And a 2014 study by the American College of Cardiology revealed a 25% jump in the number of heart attacks on the Monday after the time change. (Learn how daylight saving time affects your health, according to science.)
Last year the Senate passed the “Sunshine Protection Act” to make DST permanent in response to public disdain for the twice annual time change, but the bill has stalled in the House.
Fewer than 40% of the world’s countries observe DST today. It makes almost no difference in equatorial countries because the number of daylight hours remains mostly consistent throughout the year. It also makes less of a difference in regions of the globe between the northern Tropic of Cancer (that runs through central Mexico, the African Sahel, central India, southern China) and the southern Tropic of Capricorn (that traverses northern Chile and Argentina, southern Brazil, southern Africa and Australia).
Where DST matters the most is above and below these tropical latitudes. Forty-nine countries that are in whole or in part in Europe follow DST, the most of any continent, while 38 African countries have never implemented it.
To find the countries that no longer observe DST, 24/7 Tempo referenced information from Time and Date AS, a Norwegian website that’s been keeping track of time zones around the world since 1998.
Some 66 countries around the world dabbled with DST before giving it up, including 10 that used it for a year or less. Bangladesh holds the record for the shortest experiment, implementing DST in 2009 and ending it the same year due to public outcry. Syria holds the record for having observed it the longest, from 1920 to 2022. Ten other countries have ended DST in the past decade, including Brazil and Egypt.
Two U.S. states don’t follow DST: Sun-splashed Hawaii, the only U.S. state in the global tropical zone, and Arizona - which was granted a special exemption by the federal government in the 1970s on the basis that DST would keep the sun shining in the state until 9 p.m. in the summer, adding to the oppressive heat. (These are the American cities with the hottest summers.)
Arizona’s Native American reservations follow DST, however, which means that clocks can change back and forth for those taking summer road trips through the state. (Abenaa / iStock via Getty Images)