How Prayer Times Are Calculated: Angles, Methods and the Asr Schools

The times of the five daily prayers are defined by the position of the sun. Because the sun's path depends on where you are and on the date, prayer times are calculated from your latitude, longitude and time zone. Here is how each time is found.

The five times

• Fajr begins at true dawn, when the first light spreads across the eastern horizon. In calculations this is when the sun is a set angle below the horizon, usually between 15° and 20°.
• Sunrise marks the end of Fajr. It is when the top edge of the sun appears, about 0.83° below the true horizon after allowing for refraction and the sun's radius.
• Dhuhr begins just after solar noon, when the sun has passed its highest point.
• Asr begins when the shadow of an object equals its length plus the length of its shadow at noon. In the Hanafi school, the shadow must be twice the object's length, so Asr starts later.
• Maghrib begins at sunset.
• Isha begins when the evening twilight has disappeared, again defined by a solar angle, or as a fixed interval after Maghrib.

Why the methods differ

Scholars and astronomers have chosen different angles to match observations of dawn and dusk in their regions:

A larger angle gives an earlier Fajr and a later Isha. HijriTime applies the method that is standard in each country, which you can see on every city page.

High latitudes

North of about 48° latitude, around midsummer, the sun does not go far enough below the horizon for twilight to end, so a strict angle gives no Fajr or Isha time. Calculations then use a rule such as dividing the night into sevenths, or the methods of the Moonsighting Committee, which adjust twilight by season.

Precaution and your mosque

Many mosques add a few minutes of caution (ihtiyat) to the calculated times, and some follow their own long-standing timetable. Calculated times are an excellent guide, but for congregational prayer follow your local mosque. You can see the times for your city on our prayer times page.