Mark Your Calendars: British Summer Time Arrives on March 29, 2026
As winter fades into memory, many across the UK eagerly anticipate the arrival of British Summer Time (BST), promising longer days and warmer weather. In 2026, the clocks will officially "spring forward" from Greenwich Mean Time (GMT) to BST on March 29, marking the start of extended evening light. This shift will last until October 25, when GMT returns and the clocks fall back, signaling the onset of autumn.
The Little-Known Four-Minute Daylight Rule
Beyond the hour gained from the clock change, a fascinating phenomenon occurs throughout March: daylight increases by just under four minutes each day. This gradual accumulation means that by the end of the month, the impact on evening brightness is substantial, offering more than just the extra hour from BST.
According to Timeanddate.com, this daily increment adds up significantly over 31 days. For instance, in London on March 1, sunrise is at 6:45 AM and sunset at 5:40 PM, providing 10 hours, 54 minutes, and 53 seconds of daylight. By March 28, the day before BST begins, sunrise shifts to 5:45 AM and sunset to 6:26 PM, resulting in 12 hours, 41 minutes, and 50 seconds of daylight—a noticeable extension.
Daylight Hours Through Spring and Summer
After the clocks spring forward, the daylight continues to expand. On March 31, with BST in effect, London will see sunrise at 6:38 AM and sunset at 7:32 PM, offering 12 hours, 53 minutes, and 41 seconds of daylight. This progression accelerates into spring:
- By April 30, daylight spans from 5:34 AM to 8:22 PM.
- By May 31, it extends further from 4:49 AM to 9:07 PM.
The peak arrives with the summer solstice on June 21, 2026, at 09:24 AM. On this longest day of the year, sunrise in London is at 4:43 AM and sunset at 9:21 PM, delivering a remarkable 16 hours, 38 minutes, and 22 seconds of daylight. Timeanddate.com notes that this day is 8 hours and 49 minutes longer than the December solstice, with the earliest sunrise on June 17 and the latest sunset around June 24 or 25.
Sleep Impact and Historical Context of BST
While the extra daylight is welcome, the Royal Museums Greenwich highlights a downside: we lose an hour of sleep when BST starts. A simple mnemonic helps remember the change: clocks "spring forward" in spring and "fall back" in autumn.
The practice of British Summer Time originated over a century ago from a campaign aimed at maximizing daylight usage. William Willett, an early advocate and great-great-grandfather of Coldplay's Chris Martin, proposed the idea in his 1907 pamphlet, The Waste of Daylight. His initial plan involved advancing clocks by 80 minutes in four 20-minute steps, but it was simplified after his death in 1915. The Summer Time Act of 1916 established the current system of moving clocks forward by one hour during summer months, a tradition that continues to shape our seasons today.
