How prayer times are calculated
Last updated
Ready to Pray provides offline prayer start times for your selected location, using on-device calculations or the published London timetable. Congregation times are separate.
The five prayers and sunrise
The timetable shows Fajr, Dhuhr, Asr, Maghrib and Isha, plus sunrise as a useful reference. Sunrise is excluded from the five-prayer countdown. After Isha, the next prayer is the following day’s Fajr.
Choose the method your community follows
New users start with an automatic local default: the published London timetable within the M25 area where data is available, and Muslim World League elsewhere. Existing saved choices are preserved.
Open Settings on the prayer-times page to choose a calculation method. Compare its result with a trusted local timetable. If you are unsure which convention to follow, ask your local mosque or community.
Asr and minute adjustments
The Asr setting offers Standard (Shafi, Maliki and Hanbali) or Hanafi. You can also adjust each prayer by up to 60 minutes earlier or later to match a timetable you trust. These adjustments affect the displayed times, countdown, reminder plan and calendar export.
Prayer starts are different from iqamah
A calculated prayer start is not the same as a mosque’s congregation time. Ready to Pray does not currently provide mosque iqamah times or Friday congregation schedules. Follow your mosque’s published schedule for those.
Time zones, daylight saving and travel
Times follow the selected location’s time zone rather than your computer’s clock zone. Daylight-saving changes are included. Check your location when travelling; travel settings can flag a change in the device time zone, but do not track you in the background.
High latitudes and polar conditions
You can select angle-based, middle-of-the-night or one-seventh-of-the-night handling for twilight. Where normal sunrise or sunset calculations are unavailable, the default is to show unavailable events. Optional nearest-day and nearest-place estimates are also offered. Confirm an appropriate local convention before relying on an estimate.
Hijri dates and Ramadan
The Hijri display uses the device’s Umm al-Qura calendar estimate, with an optional date adjustment. Ramadan dates can be overridden with your community’s confirmed start date and month length. Umm al-Qura Isha uses a 120-minute interval during the Ramadan dates selected by the app. Moon-sighting dates should be confirmed locally.
Calculation source and limitations
London Unified Prayer Timetable: 2026–2028 · London / M25. Source and coverage.
The app bundles Adhan JS for prayer calculations and a local time-zone lookup. A prayer-time API is not required for normal calculations, including future months. City search uses the separate Open-Meteo geocoding service.
Calculated times depend on your coordinates and conventions. Use the app as a practical timetable and check settings against a reliable local source. Open-source notices are available for the bundled libraries.