# Western European Summer Time

Western European Summer Time (WEST, UTC+01:00) is a summer daylight saving time scheme, 1 hour ahead of Greenwich Mean Time and Coordinated Universal Time. It is used in:
* the Canary Islands
* Portugal (including Madeira but not the Azores)
* the Faroe Islands
The following countries also use the same time zone for their daylight saving time but use a different title:
* United Kingdom, which uses British Summer Time (BST)
* Ireland, which uses Irish Standard Time (IST) (Am Caighdeánach na hÉireann (ACÉ)). Also sometimes erroneously referred to as "Irish Summer Time" (Am Samhraidh na hÉireann).
The scheme runs from the last Sunday in March to the last Sunday in October each year. At both the start and end of the schemes, clock changes take place at 01:00 UTC+00:00. During the winter, Western European Time (WET, GMT+0 or UTC+00:00) is used.
The start and end dates of the scheme are asymmetrical in terms of daylight hours: the vernal time of year with a similar amount of daylight to late October is mid-February, well before the start of summer time. The asymmetry reflects temperature more than the length of daylight.
Ireland observes Irish Standard Time during the summer months and changes to UTC+00:00 in winter. As Ireland's winter time period begins on the last Sunday in October and finishes on the last Sunday in March, the result is the same as if it observed summer time.

## Usage

The following countries and territories use UTC+01:00 during the summer, between 1:00 UTC on the last Sunday of March and 1:00 UTC on the last Sunday of October.
* Canary Islands, regularly since 1980 (rest of Spain is CEST, i.e. UTC+02:00)
* Faroe Islands, regularly since 1981
* Ireland
** 1916–1939 summers IST
** 1940–1946 all year IST
** 1947–1968 summers IST
** 1968–1971 all year IST
** 1972– summers IST
* Portugal
** Continental Portugal
*** 1916–1921 summers WEST
*** 1924 summer WEST
*** 1926–1929 summers WEST
*** 1931–1932 summers WEST
*** 1934–1941 summers WEST
*** 1942–1945 summers WEST (1942–1945 midsummers Western European Midsummer Time|WEMT=WEST+1)
*** 1946–1966 summers WEST
*** 1966–1976 all year WEST/CET
*** 1977–1992 summers WEST
*** 1992–1996 winters WEST/CET (1993–1995 summers CEST)
*** 1996– summers WEST
** Madeira, regularly since 1982
* The United Kingdom
** 1916–1939 summers BST
** 1940–1945 all year BST (1941–1945 summers BDST=BST+1)
** 1946 summer BST
** 1947 summer BST (1947 midsummer BDST=BST+1)
** 1948–1968 summers BST
** 1968–1971 all year BST
** 1972– summers BST

### Ireland

In Ireland, since the Standard Time (Amendment) Act, 1971, Ireland has used UTC+1 in summer (officially "standard time", Irish: am caighdeánach, though usually called "summer time") and UTC+0 in winter (officially "winter time").

### Portugal

Portugal moved to Central European Time and Central European Summer Time in 1992, but reverted to Western European Time in 1996 after concluding that energy savings were small, it had a disturbing effect on children's sleeping habits as it would not get dark until 22:00 or 22:30 in summer evenings, during winter mornings the sun was still rising at 9:00, with repercussions on standards of learning and school performance, and insurance companies reported a rise in the number of accidents.

### United Kingdom

Starting in 1916, the dates for the beginning and end of BST each year were mandated by the Parliament of the United Kingdom. From 1940 to 1945, the country used British Summer Time in the winter months and British Double Summer Time, a further hour ahead of GMT, in the summer months. From 1968 to 1971, the country used BST throughout the year. In February 2002, the Summer Time Order 2002 changed the dates and times to match European rules for moving to and from daylight saving time.

## Start and end dates of British Summer Time and Irish Standard Time

| Year | Begins (GMT) | Ends (GMT) | UK Notes | Ireland Notes |
| 2025 | Sun 30 March 01:00 | Sun 26 October 01:00 | | |
| 2024 | Sun 31 March 01:00 | Sun 27 October 01:00 | | |
| 2023 | Sun 26 March 01:00 | Sun 29 October 01:00 | | |
| 2022 | Sun 27 March 01:00 | Sun 30 October 01:00 | | |
| 2021 | Sun 28 March 01:00 | Sun 31 October 01:00 | | |
| 2020 | Sun 29 March 01:00 | Sun 25 October 01:00 | | |
| 2019 | Sun 31 March 01:00 | Sun 27 October 01:00 | | |
| 2018 | Sun 25 March 01:00 | Sun 28 October 01:00 | | |
| 2017 | Sun 26 March 01:00 | Sun 29 October 01:00 | | |
| 2016 | Sun 27 March 01:00 | Sun 30 October 01:00 | | |
| 2015 | Sun 29 March 01:00 | Sun 25 October 01:00 | | |
| 2014 | Sun 30 March 01:00 | Sun 26 October 01:00 | | |
| 2013 | Sun 31 March 01:00 | Sun 27 October 01:00 | | |
| 2012 | Sun 25 March 01:00 | Sun 28 October 01:00 | | |
| 2011 | Sun 27 March 01:00 | Sun 30 October 01:00 | | |
| 2010 | Sun 28 March 01:00 | Sun 31 October 01:00 | | |
| 2009 | Sun 29 March 01:00 | Sun 25 October 01:00 | | |
| 2008 | Sun 30 March 01:00 | Sun 26 October 01:00 | | |
| 2007 | Sun 25 March 01:00 | Sun 28 October 01:00 | | |
| 2006 | Sun 26 March 01:00 | Sun 29 October 01:00 | | |
| 2005 | Sun 27 March 01:00 | Sun 30 October 01:00 | | |
| 2004 | Sun 28 March 01:00 | Sun 31 October 01:00 | | |
| 2003 | Sun 30 March 01:00 | Sun 26 October 01:00 | | |
| 2002 | Sun 31 March 01:00 | Sun 27 October 01:00 | UK adopts EU practice | Ireland adopts EU Practice |
| 2001 | Sun 25 March 01:00 | Sun 28 October 01:00 | | |
| 2000 | Sun 26 March 01:00 | Sun 29 October 01:00 | | |
| 1999 | Sun 28 March 01:00 | Sun 31 October 01:00 | | |
| 1998 | Sun 29 March 01:00 | Sun 25 October 01:00 | | |
| 1997 | Sun 30 March 01:00 | Sun 26 October 01:00 | | |
| 1996 | Sun 31 March 01:00 | Sun 27 October 01:00 | | |
| 1995 | Sun 26 March 01:00 | Sun 22 October 01:00 | | |
| 1994 | Sun 27 March 01:00 | Sun 23 October 01:00 | | |
| 1993 | Sun 28 March 01:00 | Sun 24 October 01:00 | | |
| 1992 | Sun 29 March 01:00 | Sun 25 October 01:00 | | |
| 1991 | Sun 31 March 01:00 | Sun 27 October 01:00 | | |
| 1990 | Sun 25 March 01:00 | Sun 28 October 01:00 | | |
| 1989 | Sun 26 March 01:00 | Sun 29 October 01:00 | | |
| 1988 | Sun 27 March 01:00 | Sun 23 October 01:00 | | |
| 1987 | Sun 29 March 01:00 | Sun 25 October 01:00 | | |
| 1986 | Sun 30 March 01:00 | Sun 26 October 01:00 | | |
| 1985 | Sun 31 March 01:00 | Sun 27 October 01:00 | | |
| 1984 | Sun 25 March 01:00 | Sun 28 October 01:00 | | |
| 1983 | Sun 27 March 01:00 | Sun 23 October 01:00 | | |
| 1982 | Sun 28 March 01:00 | Sun 24 October 01:00 | | |
| 1981 | Sun 29 March 01:00 | Sun 25 October 01:00 | | |
| 1980 | Sun 16 March 02:00 | Sun 26 October 02:00 | | |
| 1979 | Sun 18 March 02:00 | Sun 28 October 02:00 | | |
| 1978 | Sun 19 March 02:00 | Sun 29 October 02:00 | | |
| 1977 | Sun 20 March 02:00 | Sun 23 October 02:00 | | |
| 1976 | Sun 21 March 02:00 | Sun 24 October 02:00 | | |
| 1975 | Sun 16 March 02:00 | Sun 26 October 02:00 | | |
| 1974 | Sun 17 March 02:00 | Sun 27 October 02:00 | | |
| 1973 | Sun 18 March 02:00 | Sun 28 October 02:00 | | |
| 1972 | Sun 19 March 02:00 | Sun 29 October 02:00 | | |
| 1971 | | Sun 31 October 02:00 | BST all year ends | IST all year ends |
| 1970 | | | BST all year | IST all year |
| 1969 | | | BST all year | IST all year |
| 1968 | Sun 18 February 01:00 | | BST all year begins | IST all year begins |
| 1967 | Sun 19 March 02:00 | Sun 29 October 02:00 | | |
| 1966 | Sun 20 March 02:00 | Sun 23 October 02:00 | | |
| 1965 | Sun 21 March 02:00 | Sun 24 October 02:00 | | |
| 1964 | Sun 22 March 02:00 | Sun 25 October 02:00 | | |
| 1963 | Sun 31 March 02:00 | Sun 27 October 02:00 | | |
| 1962 | Sun 25 March 02:00 | Sun 28 October 02:00 | | |
| 1961 | Sun 26 March 02:00 | Sun 29 October 02:00 | | |
| 1960 | Sun 10 April 02:00 | Sun 2 October 02:00 | | |
| 1959 | Sun 12 April 02:00 | Sun 4 October 02:00 | | |
| 1958 | Sun 20 April 02:00 | Sun 5 October 02:00 | | |
| 1957 | Sun 14 April 02:00 | Sun 6 October 02:00 | | |
| 1956 | Sun 22 April 02:00 | Sun 7 October 02:00 | | |
| 1955 | Sun 17 April 02:00 | Sun 2 October 02:00 | | |
| 1954 | Sun 11 April 02:00 | Sun 3 October 02:00 | | |
| 1953 | Sun 19 April 02:00 | Sun 4 October 02:00 | | |
| 1952 | Sun 20 April 02:00 | Sun 26 October 02:00 | | |
| 1951 | Sun 15 April 02:00 | Sun 21 October 02:00 | | |
| 1950 | Sun 16 April 02:00 | Sun 29 October 02:00 | | |
| 1949 | Sun 3 April 02:00 | Sun 30 October 02:00 | | |
| 1948 | Sun 14 March 02:00 | Sun 31 October 02:00 | | |
| 1947 | | Sun 2 November 02:00 | Back to GMT | Back to GMT |
| 1947 | Sun 13 April 02:00 | Sun 10 August 02:00 | BDST (2 hours ahead) | IST / no DST |
| 1947 | Sun 16 March 02:00 | | BST begins | IST begins |
| 1946 | Sun 14 April 02:00 | Sun 6 October 02:00 | | Back to GMT (Oct) |
| 1945 | | Sun 7 October 02:00 | Back to GMT | IST |
| 1945 | Mon 2 April 01:00 | Sun 15 July 01:00 | BDST (2 hours ahead) | IST / no DST |
| 1944 | Sun 2 April 01:00 | Sun 17 September 01:00 | BDST (2 hours ahead) | IST / no DST |
| 1943 | Sun 4 April 01:00 | Sun 15 August 01:00 | BDST (2 hours ahead) | IST / no DST |
| 1942 | Sun 5 April 01:00 | Sun 9 August 01:00 | BDST (2 hours ahead) | IST / no DST |
| 1941 | Sun 4 May 01:00 | Sun 10 August 01:00 | BDST (2 hours ahead) | IST / no DST |
| 1940 | Sun 25 February 02:00 | | BST 1940–1945 | IST 1940–1946 |
| 1939 | Sun 16 April 02:00 | Sun 19 November 02:00 | | |
| 1938 | Sun 10 April 02:00 | Sun 2 October 02:00 | | |
| 1937 | Sun 18 April 02:00 | Sun 3 October 02:00 | | |
| 1936 | Sun 19 April 02:00 | Sun 4 October 02:00 | | |
| 1935 | Sun 14 April 02:00 | Sun 6 October 02:00 | | |
| 1934 | Sun 22 April 02:00 | Sun 7 October 02:00 | | |
| 1933 | Sun 9 April 02:00 | Sun 8 October 02:00 | | |
| 1932 | Sun 17 April 02:00 | Sun 2 October 02:00 | | |
| 1931 | Sun 19 April 02:00 | Sun 4 October 02:00 | | |
| 1930 | Sun 13 April 02:00 | Sun 5 October 02:00 | | |
| 1929 | Sun 21 April 02:00 | Sun 6 October 02:00 | | |
| 1928 | Sun 22 April 02:00 | Sun 7 October 02:00 | | |
| 1927 | Sun 10 April 02:00 | Sun 2 October 02:00 | | |
| 1926 | Sun 18 April 02:00 | Sun 3 October 02:00 | | |
| 1925 | Sun 19 April 02:00 | Sun 4 October 02:00 | | |
| 1924 | Sun 13 April 02:00 | Sun 21 September 02:00 | | |
| 1923 | Sun 22 April 02:00 | Sun 16 September 02:00 | | |
| 1922 | Sun 26 March 02:00 | Sun 8 October 02:00 | | |
| 1921 | Sun 3 April 02:00 | Sun 2 October 02:00 | | |
| 1920 | Sun 28 March 02:00 | Sun 24 October 02:00 | | |
| 1919 | Sun 30 March 02:00 | Sun 28 September 02:00 | | |
| 1918 | Sun 24 March 02:00 | Sun 29 September 02:00 | | |
| 1917 | Sun 8 April 02:00 | Sun 16 September 02:00 | | |
| 1916 | Sun 21 May 02:00 | Sun 1 October 02:00 | | Abolition of DMT |
Note: Until 1 October 1916 time in all of Ireland was based on Dublin Mean Time, GMT − 25 minutes.