Methodology
How are UK prayer times calculated?
Updated 2026-09-08
This site defaults to London Unified for London, Watford, Slough and Woking. Other listed cities default to Muslim World League (Fajr 18°, Isha 17°) computed locally from city coordinates. Times are baked into HTML daily and verified by automated checks.
In detail
No third-party prayer-time API is used. Outside London, the adhan astronomical library computes times from latitude, longitude and date, with British Summer Time handled automatically.
At northern latitudes (Aberdeen, Inverness, Glasgow, Edinburgh and others) the sun may not reach 18° below the horizon in summer. When that happens, Fajr and Isha use a documented one-seventh-of-the-night adjustment, disclosed on the city page.
Asr can be viewed as Standard (shadow = length) or Hanafi (shadow = 2× length).