Workers will change the time on more than 1,000 clocks at the Queen’s official residences as British Summer Time comes to an end this weekend.
Royal Collection Trust staff will spend more than 40 hours altering the timepieces at Buckingham Palace, Windsor Castle and the Palace of Holyroodhouse.
Clocks go back an hour in the early hours of Sunday when the UK switches to Greenwich Mean Time.
A team of horological conservators will work through the weekend to adjust the clocks, including 450 timepieces at Windsor Castle, 600 at Buckingham Palace and 50 at the Palace of Holyroodhouse.
The Royal Collection contains some of the finest historic clocks in existence, with many on display for visitors at Windsor and Holyroodhouse.
They reflect mechanical innovation over the centuries and the tastes of successive monarchs.
Among the 1,500 timepieces in the Royal Collection are musical clocks, astronomical clocks, miniature clocks and turret clocks.