The time change means we all go back to observing Greenwich mean time (GMT).
Royal Collection Trust staff will spend more than 40 hours altering the 1,000 timepieces at the Queen's official residences at Buckingham Palace, Windsor Castle and the Palace of Holyroodhouse in Edinburgh.
Putting the clocks back happens at 2 am because the change in hour backwards in autumn means the time remains within the same day to minimise confusion in those who must be up and about.
The concept of daylight-saving and changing the clocks was introduced by the 1916 Summer Time Act.
Those of you who do manage to get an extra hour’s sleep on Sunday can look forward to next March.
The clocks will next move forward one hour at 1am on Sunday, March 28. They will go back on October 31.