How Islamic Prayer Times Are Calculated
The five daily prayers follow the sun, not the clock. Here is how each prayer time is derived, the main calculation methods, and why times vary between cities.
Each prayer follows the sun
Fajr begins at dawn (a set sun-depression angle below the horizon); Dhuhr just after the sun passes its zenith; Asr when an object's shadow reaches a defined length; Maghrib at sunset; and Isha when the evening twilight disappears.
Calculation methods
Different authorities use slightly different sun angles for Fajr and Isha. Umm al-Qura (used in Saudi Arabia) sets Fajr at 18.5° and times Isha a fixed interval after Maghrib; other methods (MWL, Egyptian, ISNA) use their own angles, causing small differences.
Why times differ by city
Because prayer times depend on the sun's position at your exact latitude and longitude, two cities — even in the same country — can differ by several minutes. That is why an accurate calculator needs your location and date.