When Do the Clocks Go Forward in 2027? Sunday 28 March, 1am GMT

UK clocks go forward one hour on Sunday 28 March 2027, when 1am Greenwich Mean Time (GMT) becomes 2am British Summer Time (BST), according to GOV.UK and Royal Museums Greenwich. The clocks go back on Sunday 31 October 2027. The U.S. changes two weeks earlier, so London is 4 hours ahead of New York from 14 to 27 March instead of 5.

When do the clocks go forward in 2027?

GOV.UK says that “in the UK the clocks go forward 1 hour at 1am on the last Sunday in March” and back at 2am on the last Sunday in October. The last Sundays of 2027 are 28 March and 31 October.

Change	Date	What happens
Clocks go forward	Sunday 28 March 2027	1am GMT becomes 2am BST
Clocks go back	Sunday 31 October 2027	2am BST becomes 1am GMT

The Summer Time Act 1972, as amended in 2002, defines the summer time period as beginning “at one o’clock, Greenwich mean time, in the morning of the last Sunday in March”. GOV.UK gives the time as 1am without naming the zone; the reference to GMT comes from the Act. The night of 27 to 28 March is one hour shorter. For the autumn change, see our report on the clocks going back on 25 October 2026.

How does the time difference with the U.S. and Sydney change?

The United States moves first. The National Institute of Standards and Technology (NIST) says daylight saving time “begins at 2:00 a.m. on the second Sunday of March”, which is 14 March in 2027. New York is on Eastern Time (ET). Sydney is in New South Wales (NSW), where the NSW Government lists the end of daylight saving as “Sunday 4 April 2027”. The table shows the gap as London time ahead of each city, computed from those dates.

London compared with	Before 14 March	14 to 27 March	From 28 March	From 4 April
New York	5 hours ahead	4 hours ahead	5 hours ahead	5 hours ahead
Chicago	6 hours ahead	5 hours ahead	6 hours ahead	6 hours ahead
Los Angeles	8 hours ahead	7 hours ahead	8 hours ahead	8 hours ahead
Sydney	11 hours behind	11 hours behind	10 hours behind	9 hours behind

London is ahead of the three U.S. cities, and Sydney is ahead of London. A call fixed for 9am in New York is 2pm in London before 14 March, 1pm from 14 to 27 March and 2pm again from 28 March. The longer overview of every 2027 change in the U.S., EU and Australia is in our clock changes 2027 story.

What happens to sunrise and sunset in London, Edinburgh and Belfast?

The U.S. Naval Observatory (USNO) computed sunrise and sunset for the day before the change, the day of the change and the day after. The times are local clock times: GMT on 27 March, and BST on 28 and 29 March.

City	Sat. 27 March (GMT), sunrise / sunset	Sun. 28 March (BST), sunrise / sunset	Mon. 29 March (BST), sunrise / sunset
London	05:48 / 18:25	06:46 / 19:27	06:43 / 19:28
Edinburgh	05:57 / 18:40	06:55 / 19:42	06:52 / 19:44
Belfast	06:09 / 18:50	07:07 / 19:52	07:04 / 19:54

In London, sunrise is about an hour later on the clock on 28 March than on 27 March, and sunset is more than an hour later, by the USNO figures.

What to check before the clocks change

Print the free card below and mark the date. These steps are our advice, not an official list.

• Check ovens, car dashboards and wall clocks that you set by hand.
• Set a reminder for Saturday 27 March 2027, the evening before.
• Plan for an hour less sleep on the night of 27 to 28 March.
• Check calls and travel with the U.S. between 14 and 27 March, when London is 4 hours ahead of New York.
• Mark Sunday 31 October 2027 for the clocks going back.

The March printable calendar has room for both dates, and the daylight saving time guide covers the U.S. rule. Next year’s days off are in UK bank holidays 2027.