Why the UK Turns Its Clocks Back on 25 October 2026

At 2am on Sunday 25 October 2026, clocks across the UK go back one hour to 1am, ending British Summer Time (BST) and returning to Greenwich Mean Time (GMT). The change gives people an extra hour by the clock that night; after it, daylight arrives earlier in the morning and fades earlier in the evening. The Summer Time Act 1972 provides the current statutory framework for summer time in Great Britain.

What happens when the clocks go back in October

The autumn change repeats the hour between 1am and 2am. A clock showing 1:59am moves back to 1am, so that hour occurs twice. The shift applies to the seasonal time arrangement; it does not change the number of daylight hours in the day.

Phones and other connected devices usually adjust automatically, while clocks that do not connect to a network may need to be changed by hand. For anyone with an overnight schedule or an appointment near the change, the repeated hour is the detail to keep in mind: local clock time alone can be ambiguous during that interval. After the switch, the time shown in the UK is GMT.

The date and time mark the end of the summer-time period, rather than a change in the underlying length of the day. In ordinary terms, the labels on the clock shift relative to daylight: mornings become lighter by the clock, and evenings darker earlier.

How British Summer Time became a seasonal convention

The clock change is often explained through a simple origin story, but daylight-saving proposals developed over time and should not be reduced to one person or one motive. The seasonal system is a convention for setting clocks at different points in the year so that clock time better matches the changing pattern of daylight.

In the UK, the familiar cycle is a move forward in spring to BST and a move back in autumn to GMT. The same clock time can therefore correspond to different positions of the sun across the seasons. The October change closes the summer-time period; it does not create or remove daylight.

That distinction helps explain why the change can feel different across the day. A journey or other activity taking place at a fixed clock time may fall in brighter morning conditions after the switch, while people leaving work or school later in the day may find that daylight has already faded. The change rearranges when daylight falls relative to the clock, rather than extending daylight overall.

What the Summer Time Act 1972 governs

The Summer Time Act 1972 sets out the statutory basis relating to summer time in Great Britain. It is the legal framework relevant to the seasonal clock arrangement, distinct from the broader history of proposals and debate about how people might use daylight.

The Act is the key legal reference for the current framework. Practical dates and instructions for households are published by the UK Government. These are related but distinct parts of the picture: historical accounts describe how the idea developed, legislation provides the legal basis in Great Britain, and government information communicates the dates of a particular clock change.

The supplied legal source is the Summer Time Act 1972 on legislation.gov.uk. Its role here is to establish the statutory framework; the date and time of the 2026 change are the practical details that tell readers when the autumn adjustment occurs.

What changes in everyday life after the switch

The clock change affects routines tied to a particular time, including travel, work and appointments. A morning journey that previously took place in dim light before sunrise may take place in brighter conditions, while an evening journey at the same clock time may happen after daylight has faded. The effect depends on the time of the activity, but the broad shift is toward earlier daylight in the morning and earlier darkness in the evening.

There is an extra hour by the clock overnight because the interval from 1am to 2am repeats. The day does not gain an hour of daylight: the clock is reset so that morning and evening hours are labelled differently. Connected devices usually update automatically, but manual clocks and plans that depend on the repeated hour may need checking.

For the 2026 change, confirm that clocks show GMT after the switch and check any manual clocks or overnight plans. The next seasonal change is the spring move to BST, when clocks go forward by one hour.

Source: legislation.gov.uk