Why Do Prayer Times Differ Between Mosques and Apps?

Compare the inputs before comparing the clock time

Two timetables can use the same city name and still produce different results because they use different coordinates, time zones, elevation assumptions, calculation methods, safety margins or Asr conventions. Some mosques also publish congregation times rather than the beginning of the prayer window.

Fajr and Isha

These are especially sensitive to the twilight rule. A larger solar-depression angle generally produces an earlier Fajr and a later angle-based Isha. Umm al-Qura commonly uses a fixed interval after Maghrib for Isha instead of an Isha angle, which is why it should not be compared as though it used the same rule as an angle-based timetable.

Maghrib and Iftar

Maghrib follows sunset, but a timetable can add a small safety margin. Nearby cities can also differ by several minutes because longitude and local horizon conditions differ. When fasting, follow the reliable local timetable or authority you normally use if it intentionally includes such a margin.

How to diagnose a difference

1. Confirm the exact city or coordinates.
2. Check the time zone and daylight-saving status.
3. Compare the Fajr/Isha method.
4. Check Hanafi versus standard Asr.
5. Ask whether the mosque table is prayer-start time or iqamah time.

Common five-minute mysteries

A difference of a few minutes can come from rounding, a safety margin or a nearby coordinate. A difference of tens of minutes in Fajr or Isha is more likely to point to a different twilight method, while a large Asr difference often points to Hanafi versus standard shadow factor.

Congregation time is not prayer-start time

Many mosque apps show iqamah prominently. Comparing an iqamah time with an astronomical start time is not a valid accuracy test because they answer different questions.

Coordinates can matter inside one city

Large metropolitan areas cover enough east-west distance for sunrise and sunset to shift. A mosque may also calculate from its exact location while an app uses the city centre. Compare coordinates before treating a few minutes as an error.

Rounding and safety margins

Some published timetables round to a whole minute or intentionally add/subtract a small margin. That should be documented rather than hidden inside the method name.

DST and time-zone databases

A correct astronomical result can still appear an hour wrong if a site applies the wrong civil-time offset. For future dates, use the IANA time-zone rule for the location rather than the visitor’s current browser offset.