Why Do the Clocks Go Back in October? The Real Reason

The clocks go back to return to the standard time that fits the sun. In summer, British Summer Time moves the evening light later by one hour, which most people like. In winter, the same setting would push sunrise very late. Going back to GMT means the sun comes up an hour earlier by the clock, in time for the school run and the commute.

The change is about when daylight arrives relative to waking hours, not about the amount of daylight. Days are short in December whatever the clock says.

At the winter solstice in London the sun rises at about 07:55 GMT and sets at about 15:55. If the clocks stayed on BST, sunrise would be about 08:55 and sunset about 16:55. In Edinburgh sunrise would not come until around 09:40, and in the far north of Scotland it would be even later. Many children would walk to school in the dark and many workers would start their day with no light at all.

This is exactly what happened in the winter of 1968 to 1969, when the UK tried staying on British Standard Time (GMT+1) all year. The experiment ran for three years, was unpopular in Scotland and the north of England because of the dark mornings, and was ended in 1971.

Two decisions sit behind the date. The first is the season: late October is when the evenings have drawn in and the shift back to GMT starts to matter. The second is the weekday. A Sunday change disrupts the fewest people, since most offices, schools and shifts are closed or quieter.

The rule is also harmonised with the rest of Europe. EU countries all change at 01:00 UTC on the last Sunday of October, which is 02:00 BST in London (clocks go back to 01:00), 03:00 CEST in Paris (back to 02:00) and 04:00 EEST in Athens (back to 03:00). Using a common instant keeps trains, flights, markets and broadcasting in step.

At 02:00 BST the time goes back to 01:00 GMT. This means the hour between 01:00 and 02:00 happens twice that night. Systems that log local time have to cope with a repeated hour, so servers and financial systems run on UTC. The change gives you one extra hour in bed, and the day is 25 hours long.

Mobile phones, computers and most smart devices adjust automatically because they get the rule from a time zone database. Manually set clocks, such as ovens, cars and some central heating timers, need to be changed by hand.

The price of lighter mornings is darker evenings. In London, sunset on the Monday after the clocks go back is around 16:40, down from about 17:40 the week before, and it falls to about 15:55 in mid-December. For people who finish work at 17:00 the commute home is then in the dark for the whole winter.

Road-safety bodies note that the weeks after the clocks go back see more collisions involving pedestrians at dusk, which is why campaigns encourage high-visibility clothing and lights on bikes at this time.

A popular myth says the clocks change for farmers. In fact farmers have historically been among the groups that opposed it, because cows and crops follow the sun and a clock change moves the milk collection and market schedule around them. The system was designed for towns, factories and fuel use, not farms.

2026: clocks go back on Sunday, 25 October 2026, and forward again on Sunday, 28 March 2027.

2027: clocks go back on Sunday, 31 October 2027, and forward again on Sunday, 26 March 2028.

2028: clocks go back on Sunday, 29 October 2028, and forward again on Sunday, 25 March 2029.

2029: clocks go back on Sunday, 28 October 2029, and forward again on Sunday, 31 March 2030.

2030: clocks go back on Sunday, 27 October 2030, and forward again on Sunday, 30 March 2031.