If your oven clock has been an hour wrong for the past few weeks, you are not alone. Clocks across the UK and the European Union went back on 25 October, and most of the United States followed on 1 November. Your phone sorted itself out overnight. The car and the microwave probably did not.
Every year the same questions come back. Why do we do this at all? Who decided it? And weren’t politicians supposed to be ending it? Here is the short history, the rules as they stand in late 2026, and an honest look at whether the twice-yearly switch is finally on its way out.
The basic idea
Daylight saving time (DST), called summer time in Europe, moves the clocks one hour forward in spring and one hour back in autumn. The amount of daylight stays the same, but more of it falls in the evening by the clock and less in the early morning, when many people are asleep anyway. In winter, clocks return to “standard time”, which sits closer to the sun’s actual position in the sky.
A short history: it started as a wartime fuel saver
Germany and Britain, 1916
The idea of shifting the clocks for summer is older than the law. In Britain, a builder named William Willett made the case in a 1907 pamphlet, The Waste of Daylight, according to Royal Museums Greenwich. He died before it happened.
What finally pushed governments to act was the First World War. Germany was the first country to adopt it, in 1916, to save fuel, and Britain followed a few weeks later. During the Second World War, Britain went further with “British Double Summer Time”, running two hours ahead of Greenwich Mean Time in summer and one hour ahead in winter. Between 1968 and 1971 it tried leaving the clocks forward all year, then abandoned the experiment.
America: war time, chaos, then a federal law
The US first brought in DST in 1918, then scrapped the national rule after the First World War and left it to local choice. According to the Congressional Research Service’s report on daylight saving time, updated in July 2026, the country ran year-round “War Time” from 1942 to 1945, and then the patchwork returned.
The Uniform Time Act of 1966 brought some order, setting DST from the last Sunday in April to the last Sunday in October. After the 1973 oil embargo, Congress even tried year-round DST from January 1974, but amended the trial within the year to bring back standard time for part of the winter. The current US dates come from the Energy Policy Act of 2005, which took effect in 2007.
The rules today
United States
The US National Institute of Standards and Technology (NIST) sets out the current US schedule:
- Clocks go forward at 2am local time on the second Sunday in March.
- Clocks go back at 2am local time on the first Sunday in November, so the hour from 1am to 2am happens twice.
That puts the US on DST for about 238 days, roughly 65% of the year.
Not everyone takes part. NIST lists Hawaii, Arizona, American Samoa, Guam, Puerto Rico and the US Virgin Islands as places that do not observe DST, and the CRS adds the Northern Mariana Islands. Arizona has an exception within the exception: the Navajo Nation does change its clocks.
The European Union and the UK
Across the EU, the rule comes from a 2001 directive. The text of Directive 2000/84/EC says summer time begins at 1am Greenwich Mean Time on the last Sunday in March and ends at 1am GMT on the last Sunday in October. Because the change is pinned to GMT, every EU country switches at the same moment, whatever its local time.
The UK left the EU but kept the same dates. The government’s clock change page puts it plainly: clocks go forward at 1am on the last Sunday in March and back at 2am on the last Sunday in October. The summer setting is British Summer Time (BST); the winter one is Greenwich Mean Time (GMT).
Notice that Europe and the US do not change on the same weekends. For a week or two each spring and autumn, the time gap between London and New York shrinks by an hour.
Most of the world does not bother
According to timeanddate’s DST statistics, 70 countries use DST in 2026, which is fewer than 40% of the world’s countries. More than 140 have tried it at some point, and about half of those have since given it up.
Is it ending?
Both sides of the Atlantic have voted to stop changing the clocks. Neither has actually stopped.
Europe: a 2019 vote that went nowhere (yet)
On 26 March 2019, the European Parliament voted 410 to 192, with 51 abstentions, to end seasonal clock changes from 2021. Each country would pick permanent summer or permanent winter time. The proposal followed a public consultation that drew 4.6 million responses, 84% of them in favour of scrapping the change.
But a new EU law needs the member states too, and they never agreed. A June 2026 note from the Council of the EU says progress “stalled in 2019”. Poland proposed a two-year trial of permanent summer time in 2025, but member states asked for more analysis. The European Commission launched a study in February 2026, looking at ten different scenarios, and expects to finish it by the end of 2026.
United States: halfway through Congress
The US bill is called the Sunshine Protection Act. It would make daylight saving time permanent, meaning lighter evenings all year and darker winter mornings. States that already skip DST, such as Arizona and Hawaii, could stay on their current standard time.
A version passed the Senate in 2022 but died in the House. The current version, H.R. 139, went further: the House of Representatives passed it on 14 July 2026 by 308 votes to 117. It went to the Senate the next day and was referred to the Commerce, Science and Transportation Committee. As of mid-November 2026, the official record shows no further Senate action, so it is not law.
The CRS counts 19 US states that have passed their own permanent-DST laws since 2018, but states cannot adopt year-round DST on their own. Federal law lets a state stay on standard time all year, not on summer time, so those state laws only kick in if Congress allows it.
The arguments for and against
Health and sleep
Sleep specialists are among the most vocal critics, and they want the opposite of what the US bill does. The American Academy of Sleep Medicine’s updated position statement, published in January 2024, says the US should end seasonal changes “in favor of permanent standard time, which aligns best with human circadian biology.” Their reasoning is that the body clock is regulated by the timing of light and darkness. Permanent summer time would leave many winter mornings dark, pulling the body clock out of step with the social clock.
The AASM also links the switch itself to risks for physical and mental health and safety. In spring, everyone loses an hour of sleep on the same night. Still, the wider evidence is mixed. The CRS notes that some studies link the spring switch to more heart attacks, while others find no link at all.
Energy savings: real, but tiny
Saving fuel was the original point. When the US extended DST in 2007, the Department of Energy measured the result. Its report to Congress found electricity use fell by about 0.5% on each extra day of DST, but only about 0.03% across the whole year.
Road safety
One study cited by the CRS found the risk of fatal car crashes rose by 6% after the spring change, most likely because of sleepy drivers, with no effect seen in autumn. Some research suggests DST reduces crashes over the long term, though that study’s authors think those benefits more likely come from the seasons than from DST itself.
How your phone handles it
The rules themselves are tracked in a shared reference called the Time Zone Database, maintained by IANA. It records the history of local time, UTC offsets and daylight-saving rules for many locations, and it is updated whenever governments change them (the latest release, 2026f, came out on 27 October 2026).
On an iPhone, Apple says that Date and Time settings let your device adjust automatically for time zone changes and daylight saving time. Keep “Set Time Automatically” switched on, and allow Location Services to set your time zone. If updated time zone information is available, Apple suggests restarting the device to apply it. On Android, Google’s help pages point to the Clock app’s settings, where you can turn on “Automatic date and time” and “Automatic time zone”.
Updates carry security fixes too, as our guide to what a Chrome zero-day is and how to check you’re patched explains. And if your phone dies on the night the clocks change, our tips on making your phone battery last longer might save your alarm.
When the clocks change next
Unless the law changes first, the 2027 dates are:
- United States (most areas): forward on Sunday 14 March 2027, back on Sunday 7 November 2027.
- UK and EU: forward on Sunday 28 March 2027, back on Sunday 31 October 2027.
What to take from it
- The clock change was a wartime fuel-saving measure, and the modern energy savings are very small.
- Europe voted to end it in 2019, but as of mid-2026 it was still waiting on a Commission study and agreement among member states.
- The US House passed permanent DST in July 2026; the Senate has not acted, so plan on changing your clocks in March 2027.
- Leave automatic time settings on, keep your phone updated, and save the manual job for the oven and the car.
More from News Explained: why every US flight was grounded during the FAA outage, and what inflation is and why prices keep rising.
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