Election Day in the United Kingdom is by convention a Thursday. Polls in the United Kingdom open at 7:00 and close at 22:00.

It has been suggested that this tradition arose as the best of several circumstances: Friday pay-packets would lead to more drunken voters on Fridays and weekends; having the election as far after a Sunday as possible would reduce the influence of Sunday sermons; many towns held markets on Thursdays, thus the local population would be travelling to town that day anyway.^[1]

Under the Fixed-term Parliaments Act 2011 before it was repealed in 2022, all future General Elections took place on the first Thursday in May every five years, barring special circumstances. The decision was taken by two-thirds majority of the House of Commons, or is legally determined through the act as the first Thursday in May every 5 years.

Before the Fixed Terms Parliament Act 2011 and after it was repealed, a General Election in the UK will follow the dissolution of Parliament by the Monarch on the advice of the Prime Minister of the day. The Prime Minister thus has the power to choose the date of the election. Thursday has been the customary day to hold elections since the 1930s.^[2] The Levellers proposed that elections be held on the first Thursday in every second March in The Agreement of the People in 1647.^[3]

Historically, elections took place over the course of a four-week period until 1918. Election days were then as follows:

• 14 December 1918 – Saturday
• 15 November 1922 – Wednesday
• 6 December 1923 – Thursday
• 29 October 1924 – Wednesday
• 30 May 1929 – Thursday
• 27 October 1931 – Tuesday

and elections have been on Thursdays since then:

• 14 November 1935
• 5 July 1945
• 23 February 1950
• 25 October 1951
• 26 May 1955
• 8 October 1959
• 15 October 1964
• 31 March 1966
• 18 June 1970
• 28 February 1974
• 10 October 1974
• 3 May 1979
• 9 June 1983
• 11 June 1987
• 9 April 1992
• 1 May 1997
• 7 June 2001
• 5 May 2005
• 6 May 2010
• 7 May 2015
• 8 June 2017
• 12 December 2019

Local elections in England and Wales are by statute held on the first Thursday in May. This has been changed in recent years: in 2001 they were delayed while an outbreak of foot-and-mouth disease was dealt with and in 2020 they were postponed by a year due to the COVID-19 pandemic.^[4] In 2004, 2009 & 2014 local elections were delayed in order to allow the elections to be held simultaneously with the European Parliament. However the elections were separate in 2019. In all cases, the elections were held on Thursdays.

By-elections and other UK elections are also traditionally held on Thursdays though they can be held on other days – in particular when they would otherwise clash with bank holidays. The last Parliamentary by-election not to be held on a Thursday was the Hamilton by-election of 31 May 1978. This was held on a Wednesday as the returning officer wished to avoid a clash with the opening game of the 1978 FIFA World Cup. Today, council by-elections are still occasionally held on days other than Thursday.

From 1997 to 2015, general elections occurred on the same days as the annual scheduled local government elections; however, this ended in 2017 with the local elections on 4 May and the general election on 8 June.

• Election day – most other European countries hold elections on Sundays.