It's also 100 years since the date on which we put the clocks back was switched from the third Saturday in September to the first Saturday in October. That's not how things work any more, indeed the rules for putting clocks forward and back have changed many times over many years. So I thought I'd try to summarise all the changes since British Summer Time was first introduced. It's a complicated tale that thankfully gets simpler as the years go forward. [dates & times][dates][legislation]
As an initial indication of how complicated it is, here's a quick summary of the month in which the clocks changed.
Year
Clocks forward
Clocks back
1916
May
October
1917-1924
March or April
September or October
1925-WW2
April
September
WW2
Double Summer Time
WW2-1960
April
October
1961-1967
March
October
1968-1971
Permanent Summer Time
1972-2025
March
October
We should probably start at the beginning.
1907:William Willett, a builder from Chislehurst, published a pamphlet proposing that clocks be advanced in April and put back in September. This would increase evening daylight and reduce expenditure on lighting. 1908: The Daylight Saving Bill is introduced in Parliament. It is voted down by 124 votes to 91. Winston Churchill is in favour. 1916: Germany introduces daylight saving to support the war effort so the UK follows suit, passing the Summer Time Act. ("the prescribed period shall be from two o'clock in the morning Greenwich mean time on Sunday the twenty-first day of May until two o'clock in the morning Greenwich mean time on Sunday the first day of October") 1917-1922: Summer time continues, the dates decided each year by an Order in Council.
Year
Clocks forward
Clocks back
1916
Sunday 21 May
Monday 1 October
1917
Sunday 8 April
Monday 17 September
1918
Sunday 24 March
Monday 30 September
1919
Sunday 30 March
Monday 29 September
1920
Sunday 28 March
Monday 25 October*
1921
Sunday 3 April
Monday 3 October
1922
Sunday 26 March
Sunday 8 October**
* Would have been Monday 27 September but a coal strike delayed it by four weeks
** In 1922 the morning for turning the clocks back switched from Monday to Sunday, and it's been Sunday ever since.
In summer 1922, a new Summer Time Act was passed. This set the start date as "the day next following the third Saturday in April, or, if that day is Easter Day, the day next following the second Saturday in April" and the end date as "the day next following the third Saturday in September". Like so.
Year
Clocks forward
Clocks back
1923
Sunday 22 April
Sunday 16 September
1924
Sunday 13 April*
Sunday 21 September
* Easter Day was 20th April, the third Sunday of the month, so the start of daylight saving was brought forward a week to 13th April.
1922's Summer Time Act was made permanent in 1925 so that Parliament didn't need to renew it each year. The 1925 Act also changed the end date to "the day after the first Saturday in October". This made things a lot simpler.
Years
Clocks forward
Clocks back
1925-1938
the day after the second Saturday in April (unless this is Easter Day* in which case one week earlier)
the day after the first Saturday in October
* This happened in 1924, 1927, 1930, 1933, 1935 and 1938.
In 1939 war against Germany triggered another change, this time to make best use of daylight and reduce the length of the evening blackout.
The Defence (Summer Time) Regulations... i) delayed the end of Summer Time in 1939 by seven weeks ii) introduced permanent Summer Time in 1940 iii) introduced Double Summer Time from 1941 onwards.
Clocks did not go back in autumn 1940 but did go forward in spring 1941, putting the country on GMT+2 for the first time. GMT was not observed between February 1940 and October 1945, Britain was either on Summer Time or Double Summer Time.
Year
Clocks forward
Clocks back
1939
Sunday 16 April
GMT+1
Sunday 19 November*
1940
Sunday 25 February
GMT+1
-
1941
Sunday 4 May
GMT+2
Monday 10 August
1942
Sunday 5 April
GMT+2
Monday 9 August
1943
Sunday 4 April
GMT+2
Monday 15 August
1944
Sunday 2 April
GMT+2
Monday 17 September
* The latest date the clocks have ever gone back
Extricating ourselves from Double Summer Time proved complicated. In 1945 the clocks had to go back twice, once in July and once in October. Double Summer Time was then reintroduced as an emergency measure in 1947 because of severe fuel shortages resulting from the harsh winter. 1947 is the only year the clocks changed four times.
Year
Clocks forward
Clocks back
1945
Monday 2 April*
GMT+2
Sunday 15 July AND Sunday 7 October
1946
Sunday 14 April
GMT+1
Sunday 6 October
1947
Sunday 16 March AND Sunday 13 April
GMT+2
Sunday 10 August AND Sunday 2 November
1948
Sunday 14 March
GMT+1
Sunday 31 October
1949
Sunday 3 April
GMT+1
Sunday 30 October
* The only time the clocks have ever gone forward on a Monday
Things got a little simpler in the 50s.
Years
Clocks forward
Clocks back
1950-1952
the day after the second Saturday in April (unless this is Easter Day* in which case one week earlier)
the day after the third Saturday in October
1953-1960
the day after the first Saturday in October
* This happened in 1951, 1954, 1957 and 1960**.
** 1960 was the last year the clocks went forward in April.
In 1960 the government consulted 180 organisations as part of an inquiry into the future of Summer Time. A slight majority preferred keeping Summer Time all year round but this was not adopted. Instead the statutory period of Summer Time was extended by three weeks in both spring and autumn (then in 1964 extended again by a week in the spring).
Years
Clocks forward
Clocks back
1961-1963
the last Sunday in March
the day after the third Saturday in October
1964-1967
the day after the fourth Saturday in March
After a further inquiry in 1967 the new Labour government decided to introduce British Standard Time, a three year trial in which Britain would remain on GMT+1 throughout the year. The clocks did not go back at the end of October 1968, thus effectively adopting Central European Time. In December 1970 the new Conservative government held a debate on the continuation of British Standard Time. MPs decided to end the experiment by a vote of 366 to 81.
Year
Clocks forward
Clocks back
1968
Sunday 16 February
GMT+1
-
1969
-
GMT+1
-
1970
-
GMT+1
-
1971
-
GMT+1
Sunday 31 October
After the experiment everything returned to the previous pattern for the rest of the decade. Then in 1980 the European Union introduced their first harmonisation directive. This...
i) mandated a common start date across the EU (the last Sunday in March) ii) permitted the UK & Ireland a separate finish date to the rest of the EU (who changed at the end of September) iii) harmonised the time the clocks changed (now 1am GMT, not 2am GMT)
Years
Clocks forward
Clocks back
1972-1980
the day after the fourth Saturday in March (at 2am GMT)
the last Sunday in October (at 2am GMT)
1981-1995
the last Sunday in March (at 1am GMT)
the last Sunday in October (at 1am GMT)
In 1994 the EU's seventh directive on summer-time arrangements fixed a common end date across the EU from 1995 onwards. In the opposite of what you might expect, they forced all the other EU countries to adopt the same end date as the UK, i.e. the last Sunday in October. To ease in the new arrangements, 1995's date was brought ahead by a week as a one-off.
Years
Clocks forward
Clocks back
1995
the last Sunday in March
Sunday 22 October
1996-2025
the last Sunday in March
the last Sunday in October
And so it is that for the last 30 years our clocks have gone forward on the last Sunday in March and back on the last Sunday in October, no faff, no twiddles.
Since we left the EU in 2020 it's been possible for Britain to make its own decisions on summer time but nobody's dared risk it. Any changes would lead to time zone differences on the island of Ireland, plus it's always been a hugelydivisiveissue with no solutions that suit everyone so the status quo looks likely to continue. You may not like how and when we put the clocks forward and back, but at least "the last Sunday of the month" keeps it simple.
