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:

Time in Europe:
Light Blue Western European Time / Greenwich Mean Time (UTC)
Blue Western European Time / Greenwich Mean Time (UTC)
Western European Summer Time / British Summer Time / Irish Standard Time (UTC+1)
Red Central European Time (UTC+1)
Central European Summer Time (UTC+2)
Yellow Eastern European Time / Kaliningrad Time (UTC+2)
Ochre Eastern European Time (UTC+2)
Eastern European Summer Time (UTC+3)
Green Moscow Time / Turkey Time (UTC+3)
Turquoise Armenia Time / Azerbaijan Time / Georgia Time / Samara Time (UTC+4)
 Pale colours: Standard time observed all year
 Dark colours: Summer time observed

The following countries also use the same time zone for their daylight saving time but use a different title:

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.[1] 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

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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[5]
      • 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[6][7]=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[8]
  • 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

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In Ireland, since the Standard Time (Amendment) Act, 1971, Ireland has used UTC+1 in summer (officially "standard time",[9] Irish: am caighdeánach,[10] though usually called "summer time") and UTC+0 in winter (officially "winter time").[11]

Portugal

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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.[12]

United Kingdom

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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[13] 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

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Year Begins (GMT) Ends (GMT) UK Notes Ireland Notes
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[13][14] Ireland adopts EU Practice [14][15]
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
Sun 13 April 02:00 Sun 10 August 02:00 BDST (2 hours ahead) IST / no DST
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
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.

References

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  1. ^ a b "STANDARD TIME ACT, 1968".
  2. ^ "AN tACHT UM AM CAIGHDEÁNACH, 1968".
  3. ^ "timeanddate.com webpage erroneously referring to IST as "Irish Summer Time"". Retrieved 27 August 2009.
  4. ^ "Example of Trinity College, Dublin using the term "Irish Summer Time"". Trinity College, Dublin. Retrieved 27 August 2009.
  5. ^ "Hora Legal em Portugal Continental [Standard and Summer Time in Continental Portugal]" (PDF) (in Portuguese). Astronomical Observatory of Lisbon. Retrieved 20 May 2014.
  6. ^ "Time Changes in Lisbon over the years (1925–1949); Time Zone in Lisbon, Portugal". timeanddate.com. Retrieved 20 May 2014.
  7. ^ Law, Gwillim (30 May 2001). "Time Zones of Portugal". Statoids. Retrieved 20 May 2014.
  8. ^ "Decreto Regional n.º 5/82/M, de 3 de Abril [Regional Decree 5/82/M, 3 April 1982]" (PDF). Diário da República, I Série, n.º 78, 7 de Abril de 1982 (in Portuguese). 7 April 1982. pp. 777–778. Retrieved 20 May 2014.
  9. ^ "Standard Time Act, 1968". Irish Statute Book. Attorney General. 15 July 1968.
  10. ^ "Standard time". Focal. Retrieved 17 August 2012.
  11. ^ "Standard Time (Amendment) Act, 1971". Irish Statute Book. Attorney General. 20 July 1971.
  12. ^ "Lighter Evenings (Experiment) Bill [HL]".
  13. ^ a b "Statutory Instrument 2002 No. 262—The Summer Time Order 2002".
  14. ^ a b "Directive 2000/84/EC of the European Parliament and of the Council of 19 January 2001 on summer-time arrangements".
  15. ^ "Winter Time Order, 2001".

Further reading

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  • Prerau, David. Saving the Daylight: Why We Put the Clocks Forward (ISBN 1-86207-796-7) — The Story of Summer Time/Daylight Saving Time with a focus on the UK
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