What to know about daylight saving time: Your time-change questions, answered

Today, the persistence of daylight saving time is more a matter of inertia - and the costs of changing more than a century of habit.

Electric Time technician Dan LaMoore adjusts a clock hand on a 1000-lb., 12-foot diameter clock constructed for a resort in Vietnam, Tuesday, March 9, 2021, in Medfield, Mass. AP Photo/Elise Amendola

It’s that time of year – set your clocks forward this weekend or else risk embarrassing lateness. Face a Monday known for unusual spikes in heart attacks and car crashes. Debate, once again, whether the twice-a-year routine of time change is even worth it.

This time around, you can enter the discussion with some background knowledge. Here’s what to know about why we do this, and whether we might ever be able to stop.

1. How did daylight saving time start?

It’s commonly explained that the United States adopted daylight saving time to give farmers more time to work before sunset. According to farmers, that may be a myth.


In reality, it was a global response to wartime energy demands. During World War I, countries on both sides of the conflict adopted it to maximize daylight time during typical waking hours, and thus reduce use of candles, oil and electricity, according to David Prerau, author of “Seize the Daylight: The Curious and Contentious Story of Daylight Saving Time.”

In the United States, it became the law of nearly all of the land with the Uniform Time Act of 1966.

2. What’s the point of daylight saving time now?

It no longer has as much to do with energy savings. Increasing adoption of super-efficient LED bulbs means lighting now makes up a tiny fraction of households’ energy usage.

Today, the persistence of daylight saving time is more a matter of inertia – and the costs of changing more than a century of habit.

Debates about abolishing semiannual clock shifts have raised concerns about everything from teens’ sleep habits to the sanctity of Jewish prayer, with pros and cons tied to any suggestion. A switch to year-round daylight saving time would alter winter sunrise and sunset times in ways that people in many parts of the country wouldn’t like — it was hated, in fact, when the U.S. imposed such a change in the 1970s.


Thus, the status quo wins out, and the spring-forward, fall-back cycle continues.

3. Whose idea was daylight saving time?

Benjamin Franklin frequently gets some credit, though his 18th-century suggestion wasn’t so much a serious plan to change clocks as it was a joke about waking Parisians earlier. Around the turn of the 20th century, George Hudson of New Zealand and William Willett of England are credited with making pitches to change the clocks.

Hudson’s 1895 proposal most closely resembles daylight saving time as we know it today. An entomologist who worked a day job in a Wellington post office, Hudson proposed a two-hour time change in the summer months to allow more daylight time for evening bug-collecting and other hobbies. The idea was initially met with mockery; it wasn’t until 1927 that New Zealand adopted a one-hour summertime clock shift, shortened to 30 minutes the following year.

4. Is the U.S. ending daylight saving time?

Not anytime soon, despite a close call in 2022.

The U.S. Senate shocked many Americans – including some members of the body itself – by passing a bill last year to adopt year-round daylight saving time. Days earlier, experts had testified before Congress about the negative health impacts linked to the semiannual changing of the clocks.

Nevertheless, when Congress began considering the legislation, members expressed hesitation and went on to stall the bill for months as they argued over whether the Senate should have passed it at all. House officials said members received a deluge of divided opinions from constituents and warnings from sleep scientists who insist that adopting permanent standard time instead would be healthier.


The debate came to a halt late last year – and the bill officially died with the end of the 117th Congress in early January. But some are seeking to revive it. Florida Sen. Marco Rubio (R) reintroduced the legislation this month.

That is welcome news in many parts of the country. At least 19 states in recent years have enacted laws or passed resolutions that would allow them to impose year-round daylight saving time – but only if Congress approves legislation to stop the nation’s twice-per-year time changes, according to the National Conference of State Legislatures.

5. What about other countries – do they use daylight saving time?

More than 140 countries have adopted daylight saving time for some period – but only about half of them have stuck with it, according to statistics compiled by That includes most of North America and Europe as well as Australia and New Zealand, but relatively few countries closer to the equator. In much of Asia, South America and Africa, daylight saving time was only ever adopted briefly, if at all.

That may largely be a function of geography, and of Earth’s tilted axis. Because the planet spins on an axis 23.5 degrees away from being upright, higher latitudes get varying amounts of sunlight throughout the year; it’s why we have seasons. But close to the equator, the sun is up for about 12 hours a day all year long, creating less reason to change clocks.

The United States isn’t the only country questioning the value of daylight saving time. The European Union has previously weighed ditching it, but that effort has also stalled.


6. What should I do besides changing my clocks?

Since you have to make the effort to change your clocks twice a year, emergency managers recommend adding steps to your routine – at both the start and end of daylight saving time – that can keep you prepared all year.

The Federal Emergency Management Agency encourages testing smoke alarms and carbon monoxide detectors, and replacing their batteries if not the devices themselves. FEMA says it’s also a good time to review household emergency plans and readying your home for potential power outages or extreme cold.

Good Housekeeping suggests some spring cleaning-type steps: flipping mattresses, cleaning refrigerator coils, replacing air filters.

To adjust to the beginning of daylight saving time itself, sleep experts encourage preparing for potential sleep disruptions. Some suggest using relaxation techniques to improve sleep in the days ahead of the clock shift, and to prioritize daylight exposure to help set your body’s internal clock.

The Washington Post’s Allyson Chiu, Dan Diamond, Amanda Erickson and Brittany Shammas contributed to this report.


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