Why Does Daylight Saving Time Start at 2 A.M.?
As the saying goes, "Spring forward, fall back." But why doesn't that happen at midnight?
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At 2 a.m. on Sunday, March 12, 2023, most of America (except for these two states) will set their clocks forward—or ahead—to start daylight saving time in the annual tradition beloved by some and bemoaned by others (as evidenced by some calls to get rid of daylight saving time altogether). But wouldn’t midnight make a more practical start time? Why, of all random starts, 2 a.m.?
First things first: What is daylight saving time (DST)?
On the second Sunday in March each year, clocks are set forward one hour at 2 a.m., designed to make better use of daylight while people are awake. (In the fall, by contrast, clocks are set back, leading to the popular and easy-to-remember saying, “spring forward, fall back.”) It’s a tradition that Benjamin Franklin proposed to Paris in a satirical essay he penned, (yes, that Benjamin Franklin!) but which didn’t become law in the United States until 1918.
P.S.: It’s daylight saving time, not—as is commonly but mistakenly said—daylight savings time.
So, why does daylight saving time start at 2 a.m.?
Instead of turning the clocks at midnight, as might be expected, DST starts at the seemingly random time of 2 a.m. because of the railroads. When DST was introduced during World War I, it was one of the few times when there were no trains traveling on the tracks. “Sunday morning at 2 a.m. was when they would interrupt the least amount of train travel around the country,” Michael Downing, author of Spring Forward: The Annual Madness of Daylight Saving Time, has explained.
According to the online museum WebExhibits, the 2 a.m. change was also a convenient middle ground between midnight—when changing the clocks would require the date switching back to the previous day—and later in the morning when early shift workers and churchgoers might be affected.
Who observes daylight saving time?
In America, most states observe it, with the exception of Hawaii and the majority of Arizona, plus Puerto Rico, Guam, American Samoa, the Northern Mariana Islands and the Virgin Islands. (It’s still observed in Arizona by the Navajo Nation.) However, daylight saving isn’t just an American quirk; it’s celebrated around much of the world, although countries from Japan, South Korea and India to Iceland, Egypt and Argentina opt-out. Interestingly, in the European Union countries, DST starts the last Sunday of March at 1 a.m. and ends the last Sunday in October, also at 1 a.m.
- Time: Why Does Daylight Saving Time Start at 2 A.M.?
- WebExhibits: “When We Change Our Clocks”
- Sleep.org: “How Daylight Savings Time Affects Sleep”