Sources & Methodology

Geographic data

Geographic coordinates (latitude, longitude) for each city come from official national databases, enriched and manually verified. These coordinates are critical because even a 0.1° latitude difference can shift Fajr and Isha times by several minutes.

Administrative information (country, region, department, city) is structured according to each country's official divisions: régions and départements for France, counties and districts for the UK, Bundesländer and Kreise for Germany, etc.

Postal codes and population data are used for SEO metadata and to prioritise cities in navigation. Timezone data is based on the IANA tz database (e.g., Europe/London, Europe/Paris).

Calculation algorithm

Prayer times are computed using positional astronomy formulas that determine the sun's position at any moment for a given point on Earth. The calculation engine (PrayerEngine) implements standard equations for solar declination, hour angle, and atmospheric refraction.

Each prayer is defined by a precise astronomical criterion: Fajr corresponds to astronomical dawn (sun at an angle below the horizon defined by the method), Dhuhr to solar transit + declination, Asr to a specific shadow ratio, Maghrib to sunset, and Isha to the disappearance of twilight.

Supported calculation methods: UOIF (12°) used in France, MWL — Muslim World League (18°) used in the UK, Germany, Italy, and Spain, and ISNA — Islamic Society of North America (15°). The method is automatically selected based on country.

Mosque data

Mosque and Muslim worship place data comes from OpenStreetMap (OSM), a collaborative geographic database under an open licence. Places are filtered using OSM tags 'religion=muslim' and 'amenity=place_of_worship'.

This data is periodically imported and verified for geographic consistency. The number of listed mosques varies according to OSM coverage in each country.

Quality control

Each deployment includes automated checks: prayer order verification (Fajr < Dhuhr < Asr < Maghrib < Isha), timezone validity, URL slug integrity, and canonical link consistency.

Regular consistency checks are performed between Salatna's calculated times and those published by major mosques in each covered country.