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Data and methodology

Sources and methodology.

Last updated 26 April 2026

Prayer time calculation

All prayer times on WhiskAI are computed by the Aladhan API, an open-source prayer time service maintained by IslamicNetwork. Aladhan implements the standard astronomical algorithms used by major mosques and Islamic timekeeping software worldwide. We cache responses for 24 hours per city to reduce load on the upstream service.

Calculation methods

  • United Kingdom: Muslim World League (Aladhan method 3) — Fajr at 18° below horizon, Isha at 17°. The convention used by the Muslim Council of Britain and most major UK mosques.
  • United States: Islamic Society of North America (Aladhan method 2) — Fajr and Isha both at 15° below horizon. The convention used by ISNA, ICNA, and most US Islamic centres.
  • Asr school: Default Shafi'i (Aladhan school 0). Hanafi school (school 1) available via the calculation toggle on city pages.

City coordinates

City latitude and longitude reflect each city's recognised geographic centre. For most cities this is the city hall or central business district reference point. Coordinates were verified against OpenStreetMap. Variations within a metropolitan area produce prayer-time differences of seconds, well within the precision of routine observance.

Mosque directory

Mosque listings draw from the following directories and verified against each mosque's own website where one exists:

  • Muslim Council of Britain (UK directory)
  • Salam Centre directory and Visit My Mosque directory (UK)
  • ISNA mosque directory and ICNA centre listings (US)
  • Salaam directory (international)
  • Local council records and city-published Islamic centre lists

Mosques are listed only with publicly verifiable street addresses. We do not list ad-hoc prayer rooms, family mosques, or institutions without a public location.

Hijri date

The Hijri date displayed throughout the site is provided by the Aladhan API, which uses the Umm al-Qura calendar (Saudi Arabia's official calendar). Hijri dates may differ by one day from local moonsighting in particular communities; this is normal and reflects the well-known difference between calculated and observed Hijri dates.

Population statistics

Population figures cited in city pages are drawn from the most recent UK Office for National Statistics estimates and US Census Bureau estimates available at the time of writing. We update population figures annually.

Editorial sources

Historical and community-life content draws from a combination of academic publications, mosque-published histories, regional Muslim heritage projects, and reputable news archives. Where a specific factual claim is unusual or particularly significant, we cite the source inline. For our editorial review process, see editorial policy.