House of Commons: Hours Sat & Late Sittings

Over the past 15 years, there have been major changes to reform the normal sitting hours of the House of Commons. This has had a marked effect on the standard parliamentary day: proceedings now begin earlier and the number of late sittings (where the House rises after ten o’clock in the evening) has fallen significantly. In the last session, 2014-15, the House sat after 10pm on sixteen occasions, and never after midnight.

Other changes have come about as a result of the Fixed-term Parliaments Act 2011, which coupled with the moving of the State Opening of Parliament to the springtime has led to more even session lengths.

The overall trend since 1979 has been a general reduction in the sitting hours of the House each parliamentary session and a shortening of the average length of a sitting day: from 8 hours 55 minutes in 1979-80 to 7 hours 26 minutes in the latest 2014-15 session.

This note explores the trends in sitting hours of the House of Commons since 1979, both in terms of the length of parliamentary sessions and the number of hours sat, as well as the late frequency of late sittings. Since 1999 the House of Commons has also sat in a second chamber, Westminster Hall, for which hours and days sat per session is also included. This note does not consider the work of the committees which sit separately from the House.

The source of data for this publication is the House of Commons Sessional Returns, available from the Parliament website, which has information dating back to the 1997-98 session. Earlier data is taken from the Sittings of the House returns produced by the House of Commons Journal Office.

The raw data, as prepared by the Library, has been provided as an accompanying .csv file and can be downloaded from the bottom of this page.