Who Invented Daylight Saving Time? What Studies Show

Who invented daylight saving time? Franklin's 1784 joke, the 1916 start, the 2026 House vote and what studies found about sleep when the clocks change.

Jem Jeins

10/27/20266 min read

My post contentWho invented daylight saving time? The usual answer is Benjamin Franklin, and the usual answer is wrong. The idea of moving the clock came later, was first adopted during a war, and is back in the news because the US House voted in July 2026 to make it permanent.

This article follows the history, then looks at what studies measured about sleep and health around the clock changes, and where the debate stands now. If your nights get restless around the change, Hypnagogia-Pass is one calm wind-down to consider. Most studies below are observational, and each comes with its limits.

Key takeaways

Franklin's 1784 letter about candles was a joke and never proposed changing clocks. A New Zealand entomologist suggested a clock shift in 1895, and Germany and Austria first adopted it on April 30, 1916.
In a 2025 UK Biobank study of 11,780 adults, sleep on the Sunday of the clock change was 65 minutes shorter in spring and 33 minutes longer in autumn than on the Sunday before.
A 2007 study found that people's sleep timing on free days follows the seasonal progress of dawn under standard time, but not under daylight saving time.
A 2024 meta-analysis found about 4% higher heart attack risk after the spring change, and no clear increase after the autumn change.
The House passed permanent daylight saving time 308 to 117 in July 2026. As of late October, the Senate has not voted, and the American Academy of Sleep Medicine backs standard time instead.

Who invented daylight saving time? Not Benjamin Franklin

Franklin's name is tied to the idea because of a letter he sent to the Journal de Paris. The National Archives' Founders Online edition dates it to spring 1784 and says it appeared on April 26, 1784. It is a satire, signed "A Subscriber". Franklin writes that sunlight woke him around six in the morning, then calculates that Parisians would burn about 64 million pounds of wax and tallow over the six summer months, worth roughly 96 million livres, and that daylight could save it.

His proposals are jokes: a tax on shuttered windows, rationed candles, no carriages after dark, and church bells and cannon at sunrise to wake the city. He never suggests moving the clock, which is why the Franklin Institute says he did not invent daylight saving time. Our earlier post on the November clock change and sleep covers the week the clocks go back.

Why do we have daylight saving time? The 1916 start

According to a History.com account, the idea came from entomologist George Vernon Hudson, who proposed a two-hour seasonal shift to the Royal Society of New Zealand in 1895. It did not pass. About ten years later, British builder William Willett promoted it in the UK, and Parliament never adopted it.

Germany and Austria were first, on April 30, 1916, with a one-hour shift to save electricity during the war. The US adopted it in 1918, repealed it in 1919, and President Roosevelt reinstated it in 1942. The Uniform Time Act of 1966 standardized it nationwide, and in 2007 the dates moved to March and November.

The energy argument has not held up well. The same account says most studies find the savings negligible, and some find higher costs because people in hot climates run air conditioning during the day.

What studies show about sleep and health

The newest sleep measurement is a 2025 study in the Journal of Sleep Research of 11,780 UK Biobank participants aged 43 to 78, who wore accelerometers around the October 2013 and November 2015 changes. On the Sunday of the spring change, average sleep was 65 minutes shorter than on the Sunday before. On the Sunday of the autumn change, it was 33 minutes longer, not a full hour. There was some catch-up sleep after both changes, less so in autumn.

The comparison was between different people on different Sundays, which the authors list as a limit. An older study in Current Biology in 2007 asked a different question. In a survey of 55,000 people, sleep timing on free days followed the seasonal progress of dawn under standard time, but not under daylight saving time. In 50 people tracked for eight weeks around each change, sleep and activity timing adjusted readily in autumn, while activity timing did not adjust in spring, especially in late chronotypes. The authors concluded that the human circadian system does not adjust to daylight saving time. For the body-clock basics, see our post on circadian rhythm.

For health outcomes, a 2024 meta-analysis in Deutsches Arzteblatt International pooled 12 studies from 10 countries on heart attacks. The risk was 1.04 times higher after the spring change (95% confidence interval 1.02 to 1.07) and 1.02 after the autumn change (0.99 to 1.05, which includes no difference). The authors say the spring finding may be real, but the studies differed a lot from one another.

A 2022 study in Nature Communications of all-cause deaths in 16 European countries from 1998 to 2012 found fewer deaths in the first two weeks after the spring change and more after the autumn change. It is one observational study that cannot say why, so treat it as a lead, not an answer. If a restless mind is part of your clock-change week, our guide to overthinking before sleep is a place to start.

Where the permanent daylight saving time debate stands

The Sunshine Protection Act (H.R. 139) passed the House 308 to 117 on July 14, 2026, according to the Philadelphia Inquirer. It would make daylight saving time permanent nationwide. A separate bill from Representatives Scanlon and Harrigan would instead set standard time all year.

As of October 27, Yahoo News reported that the bill sits with the Senate Commerce Committee, with no floor vote scheduled. States cannot adopt permanent daylight saving time on their own under the 1966 law, though they can stay on standard time, as Hawaii and most of Arizona do. Clocks in most of the US go back at 2 a.m. on Sunday, November 1, and forward again on March 14, 2027.

Sleep medicine groups point the other way. The American Academy of Sleep Medicine's 2023 position statement backs permanent standard time as the choice that aligns best with circadian biology, and 20 organizations endorsed it. A position statement is advice from experts, not a trial. If the change leaves you awake, what to do when you cannot sleep right now covers the night itself.

Something to try tonight

Hypnagogia is the drifting, half-lit stretch between waking and sleep. Hypnagogia-Pass is our library of 30 videos, more than 2,400 minutes in total, curated by CantSwitchOff to walk you through the hypnagogic pass: a word, then a matching picture, one after another on a dark screen, with no talking and soft background sound. No ads. It is something to try, not a treatment. You can read why we built Hypnagogia-Pass before you decide.

Your daylight saving time questions, answered

What is the purpose of daylight saving time?

Daylight saving time moves the clock forward one hour in spring so that more daylight falls in the evening. Germany and Austria first used it on April 30, 1916, to save electricity in wartime. History.com's account says most studies since then find the energy savings negligible, and some find higher costs in hot climates.

What would happen if we got rid of daylight saving time?

Nobody can say for certain, and no study here predicts it. Congress would have to act, because the 1966 law bars states from adopting permanent daylight saving time alone. Two bills are in play, one for each option, and the American Academy of Sleep Medicine favors standard time.

Which is healthier, daylight saving time or standard time?

No study here settles it, but the evidence leans one way. The American Academy of Sleep Medicine backs permanent standard time as the best match for circadian biology. A 2007 study found sleep timing on free days follows dawn under standard time, but not under daylight saving time. That research is observational and about timing, not about who is healthier.

Do you get an extra hour of sleep when daylight savings ends?

On average, no. In a 2025 UK Biobank study of 11,780 adults, sleep on the Sunday the clocks went back was about 33 minutes longer than on the Sunday before, not 60. There was some catch-up sleep that week, though less than after the spring change. Individuals vary, and the comparison was between different people.

Why can't I switch off at night after the clocks change?

We found no study that tested racing thoughts after the clock change, so this is open. Light is one cue for the body clock, and the change moves it by an hour. Our post on the body clock covers that, and a mind racing at night looks at the thoughts. Hypnagogia-Pass is one calm wind-down to try.

Know someone who's awake right now?

If you have a friend you have recently talked with about the clock change and sleep, or someone you think needs this information, send them this article. It brings them what the science says, in plain words.

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If trouble sleeping lasts for weeks, or if racing thoughts come with other symptoms that worry you, please talk with a doctor. This article is general information, not medical advice, and Hypnagogia-Pass has not been tested in a clinical trial.