17 Fascinating Facts About Daylight Saving Time

Benjamin Franklin is often credited with first proposing daylight saving in his 1784 essay, “An Economical Project.” The idea wasn’t seriously considered, however, until more than a century later when William Willetts, a British builder, fiercely advocated for it. His argument was that people like long evenings because they can do more, and that they don’t regret missing the opportunity to make the most of bright mornings in the summer as they are still sleeping.

Daylight saving time was suggested by an entomologist from New Zealand, George Hudson. In 1895, he recommended a two-hour time change because he wanted to have more daylight after work to go hunting for bugs in the summer.

The benefits of DST were first recognized during World War I, when Germany was looking for ways to save energy. Germany moved the clock forward to have more daylight while people were at work. Several countries, including the United States in 1918, followed suit for the duration of the war. DST was used again during World War II as a way to save energy for war production.

The U.S. continued to observe daylight saving time even after World War II, but there was no standard law about how to implement it. Different states did it at different times, which caused a lot of confusion. To prevent this from happening, a federal law was passed in 1966 standardizing the length and times of DST for the country. States either have to change the clocks at a specified time or stick with standard time throughout the year.

If you can help it, don’t take the SAT the day after DST starts in March. It adversely affects sleep in high school students, which leads to daytime sleepiness, deteriorated vigilance, and increased lapses. A study published in the Journal of Neuroscience, Psychology, and Economics found a strong correlation between the time shift and lower SAT scores.

Outside of Navajo Nation,Arizona residents don’t have to worry about DST and trying to remember which way the clock should be moved. Residents of the Grand Canyon State don’t bother with DST because they actually don’t want longer days. Summer days are very hot there, often reaching over 100 degrees, so people prefer them to be shorter.

Hawaii opted out of the 1966 law that standardized summer time in the country. Hawaiians really don’t need it. The state is located much further south than those in mainland United States — at a latitude similar to Mexico City — so daylight saving time provides little to no benefits. Daylight hours don’t vary much, averaging about 12 a day, regardless of the season.

Indiana has two time zones and until 2006 only a few of its counties changed their clocks in the fall and in the spring. This caused a lot of confusion as several new counties decided to use DST. Keeping track of who did and didn’t was tricky, so a bill was passed in 2005, unifying the practice throughout the state. But the law was very controversial and it made the then-governor, Mitch Daniels, unpopular.

There are a few states that observe DST but really don’t want to, so much so that local officials, including Marco Rubio from Florida, have promoted passing laws to make daylight saving time the new standard all year. Florida’s Sunshine Protection Act has passed the state legislature but still needs to be approved by Congress. A bill was put forward in Alaska to end DST as well, but it was only passed by the state’s Senate. Idaho and Illinois have made attempts to stop the changing of the clock for good as well but efforts have gone nowhere so far. Other states whose legislatures have introduced bills to end DST include Oregon, New Mexico, Michigan, Texas, and Washington.

Television viewership drops in the spring after daylight saving time takes effect. About 10% fewer people watch TV because, the assumption is, they spend more time outside as the sun sets later.

Lobbyists for the golf industry told Congress in 1986 that just one hour of extra natural light during the day would result in about $200 million in extra sales; the barbecue industry estimated that extra revenue for them would be around $100 million. The candy lobby wanted to benefit as well, claiming that one more hour of sunlight on Halloween would result in more trick or treating and therefore more candy purchases. DST was not extended to eight months, covering Halloween, until 2007.

Another movement against DST focuses on negative health outcomes. Research has shown that cluster headaches are more likely within two week of the time change, and people are more prone to car crashes because of one less hour of sleep. The incidence of heart attacks may also be higher as a result of the time change in March, and more people seek help for depression in the weeks after the transition from summer to standard time.

Some research suggests that pedestrians are significantly more likely to be killed or hit by cars after 6 p.m. in the weeks after clocks return to standard time in November. Another study found a 186% jump in the risk of being killed by a car for every mile walked, suggesting that drivers may not have properly adjusted to the new time as the sun sets earlier.

The original idea behind DST was to save electricity. Research has shown, however, that this may no longer be relevant today. Many people wake up before the sun rises and need to turn on the lights or the heat — or both — during those cold dark mornings, offsetting any energy that might be saved in the evenings.

While some countries don’t observe DST at all — for example, China, Japan, and Iceland, despite its far northern location — others do it at different times. Israel and France both start DST at the end of March, but on different days, and fall back to standard time at the end of October.

He may have not come up with the idea, but William Willetts certainly advocated for DST more than anyone else in the world. The BBC calls him “the builder who changed how the world keeps time.” One of Willetts’ great-great-grandsons is Chris Martin, who is the frontman of Coldplay, one of the most popular bands of the decade.