The iconic clock mechanism at Big Ben will be powered down at 18:00 BST on Saturday as the UK prepares to shift from British Summer Time to Greenwich Mean Time in the early hours of Sunday. According to BBC News, the Cumbria Clock Company will undertake the delicate task of adjusting the world-renowned timepiece and performing essential maintenance that cannot be completed while the mechanism operates.
Mark Crangle, a technician with the company, has described the responsibility as uniquely demanding. "All eyes look towards Big Ben, it's the most iconic clock in the country," he explained, noting that the pressure intensifies given the proximity of this adjustment to Remembrance Day on 11 November.
The team will commence their work when illumination is extinguished and the clock hands are repositioned to 12 o'clock. During the shutdown period, technicians will service components that remain inaccessible during normal operation. The mechanism will be reactivated at 01:00 GMT, at which point Crangle said observers on the nearby bridge typically respond with audible celebration—an unusual sound in central London during the early morning hours.
Crangle acknowledged his own nervousness about achieving absolute accuracy. He recounted a previous incident in Seaham, County Durham, when he mistakenly advanced a clock rather than reversing it, only discovering the error after traveling half an hour away. "You only make that mistake once," he reflected.
The seasonal time adjustment has deeper historical roots than many realize. According to reporting on the UK time change system, the current clock-change arrangement originated during the First World War, when Germany introduced daylight saving in 1916 and the UK subsequently adopted a comparable system.
Big Ben itself has a more recent history of major work. The iconic clock tower returned to regular service in November 2022 following an extensive conservation initiative that commenced in 2017, ensuring the mechanism continues to function with precision.
How extensive is the clock adjustment work across Parliament?
The task extends far beyond Big Ben's single mechanism. Parliament's clock mechanics are responsible for adjusting more than 2,000 clocks across the Parliamentary Estate during the seasonal time change, a responsibility that underscores the scale of the operation. Additionally, UK Parliament confirmed that its clock mechanics would carry out the 2026 change on the Great Clock, with dial lights switching off from 18:00 on Saturday and returning at 02:00 on Sunday.
After completing work on Big Ben, Crangle and his colleagues will proceed to adjust other timepieces throughout the capital, including the clock at Westminster Abbey. Crangle characterized the weekend as demanding but rewarding. "It's a big weekend for us, it's good fun," he said.
What happens next with UK clock changes?
The autumn adjustment marks the conclusion of British Summer Time for 2026. The next UK clock change is scheduled for 28 March 2027, when clocks will advance one hour to mark the return of BST, beginning the cycle anew.
Key Facts:
- Big Ben's clock will be switched off at 18:00 BST and reactivated at 01:00 GMT during the time change
- The Cumbria Clock Company manages the adjustment and performs maintenance on components unreachable during operation
- Parliament's mechanics adjust over 2,000 clocks across the Parliamentary Estate during seasonal transitions
- The UK's daylight saving system originated during World War I, following Germany's 1916 introduction of the practice
- The next clock change will occur on 28 March 2027 when BST returns
