A recess is a break during the parliamentary session (year) in which neither the House of Commons or the House of Lords meets to conduct business (sitting).

Parliamentary sessions begin in May or June, marked by the State Opening of Parliament. This is when the King addresses the Commons and gives a speech, outlining the government's plans for the year.

A Parliamentary session normally lasts 12 months, but sometimes the government decides to extend it.

Typically, MPs get six periods of recess a year, including Christmas, Easter and Summer. The Summer recess is normally the longest of the breaks.

Whitsun recess: a week in late May to early June
Summer recess: late July to early September
Conference recess: Mid-September to early October (accommodating the party conferences)
November recess: a long weekend in mid-November
Christmas recess: late December to early January
February recess: a week in mid-February
Easter recess: two weeks dependent on the date of Easter; usually late March or early April to mid-April

This may be disrupted in a year when there is a general election or if the State Opening of Parliament is later than usual.

During recesses from the parliamentary session, neither the Commons nor the Lords meet to conduct business. Essentially it’s a period when MPs don’t go into Parliament to debate and vote, but they’re still expected to deal with issues in their constituency the media often likes to refer to recess as a holiday, but in reality, it’s an opportunity for MPs to dedicate time to their constituency.

This includes:

responding to letters and running advice surgeries for constituents to help to solve their problems, which could be anything from housing issues to benefits being stopped;
working on party matters;
taking part in civic activities like visiting local businesses and attending school fetes.

(MPs typically spend most Fridays in their constituencies doing this sort of thing when the House is sitting, but that’s not always possible, especially for those whose seats are far from Westminster.)

MPs aren’t due to return to Parliament until September, Parliament can be recalled in times of emergency. Recent examples include honouring Jo Cox MP after her murder in 2016 and voting on whether to support air strikes against ISIS in Iraq in 2014.

Learn more here: https://guidetoprocedure.parliament.uk/articles/6L8Y5Dq2/recesses