Why the UK Turns Its Clocks Back in October

History & Heritage Desk 2026-10-25 09:56 Updated: 10:10 4 min read

The iconic Elizabeth Tower and Palace of Westminster at dusk in central London.

On Sunday 25 October 2026, clocks across the UK go back one hour: at 2am, they return to 1am and the country moves from British Summer Time (BST) to Greenwich Mean Time (GMT). The change gives people an extra hour by the clock that night, while shifting more daylight towards the morning and bringing earlier sunsets.

This is the autumn turn in the UK’s seasonal time system. It is a change to clock readings, not to the amount of daylight available. The legal framework for summer time in Great Britain is set out in the Summer Time Act 1972, though the law is only one part of a longer history of ideas about how clocks and daylight should align.

What happens when clocks go back on 25 October

The UK Government says that when British Summer Time ends, clocks go back by one hour and the UK returns to GMT. In 2026, the change happens at 2am on 25 October: the clock moves back to 1am, so the hour between 1am and 2am occurs twice. By local clock time, the night is therefore one hour longer.

The change applies across the UK and marks the end of BST for the year. The seasonal adjustment returns in spring, when clocks move forward again. For anyone arranging a journey, work or appointment around the transition, the key detail is that the same hour appears twice on the clock that night.

How the change shifts daylight through the day

Moving the clock back does not create or remove daylight. It changes the relationship between daylight and the time shown on clocks. After the October switch, sunrise and sunset are shown about an hour earlier than they would be under BST.

In everyday terms, that usually means brighter mornings and earlier darkness in the evening compared with the day before. The pattern also sits within the gradual shortening of daylight as the season changes. Exact sunrise and sunset times vary by place and date, so the one-hour shift describes the clock adjustment rather than a precise local sunrise or sunset time.

This is the practical effect of the change: the same daylight is placed at different clock times. In autumn, more of it falls earlier in the day by the clock; in spring, moving forward to BST shifts that balance towards later evenings.

Why the UK Turns Its Clocks Back in October

What the Summer Time Act 1972 establishes

The Summer Time Act 1972 provides the statutory framework for summer time in Great Britain. It is the legal reference point for the current arrangement. The annual clock changes are how people encounter that arrangement in daily life, as the country moves between BST and GMT.

The act should not be confused with the full history of daylight-saving proposals. Ideas about changing clocks seasonally developed over time, alongside discussion about fitting daylight around work, travel and everyday routines. The available account does not support attributing the system to one inventor or explaining its adoption and continued use through a single motive.

That distinction helps make sense of the convention today: legislation establishes a framework, while the broader history reflects a longer debate about organising time. The law is a clear point of reference, but it does not by itself tell the whole story of how seasonal clock changes became familiar.

Why the recurring change matters in daily life

For most people, the shift is a small clock adjustment with an immediate effect on how the day is marked. In autumn, moving back to GMT places more morning daylight on the clock face and makes evening darkness arrive earlier by the clock. The spring move to BST shifts the balance the other way.

Because the change affects the times people use for journeys, work and appointments, public guidance is useful around the transition. The Government’s clock-change page explains the basic rule: when BST ends, clocks go back one hour and the UK returns to GMT.

On 25 October 2026, the change is at 2am: clocks return to 1am, and the UK moves from BST to GMT. The repeated hour makes the night longer by clock time; after it, mornings and evenings are marked about an hour earlier than under BST.

Source: legislation.gov.uk

Context & actions About this article

Source check Sources and context

The date and one-hour change follow UK Government guidance, while the Summer Time Act 1972 provides the statutory framework for summer time in Great Britain.

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