If you compare two prayer-time apps for the same city on the same day, you will often see Fajr or Isha differ by 5–10 minutes. None of them is "wrong" — they are using different agreed-upon angles for twilight.
The choice is which Fajr/Isha angle
The angles below are how far the sun must be below the horizon to count as Fajr (or Isha). A larger angle means an earlier Fajr (and a later Isha):
- Muslim World League: 18° / 17°
- ISNA (North America): 15° / 15°
- Egyptian: 19.5° / 17.5°
- Karachi: 18° / 18°
- Umm al-Qura (Saudi Arabia): 18.5° / fixed 90 min after Maghrib (120 in Ramadan)
How to pick
- Use the regional default unless your community follows another method.
- If your local mosque publishes a timetable, follow that mosque — its imam may have applied a small offset.
- For high-latitude cities in summer, the calculation may not converge for Fajr or Isha; the page should clearly say which fallback rule was applied (QiblaWeb defaults to "middle of the night").
What QiblaWeb does
Each city page applies the regional default method automatically. You can switch on the page and the times update without a server round trip. Methodology is documented at /en/methodology.
Source
Method summary from AlAdhan — Prayer calculation methods (retrieved 2026-05-09).