How prayer times are worked out, and why apps disagree

Open two prayer apps in the same city and you may see Fajr ten or fifteen minutes apart. Neither one is broken. Each is answering the same question with a slightly different rule, and once you know the few choices behind a timetable, the differences stop being a mystery.

Indeed, prayer has been decreed upon the believers a decree of specified times.

Qur’an, An-Nisa 4:103 (Sahih International)

Dhuhr and Maghrib are the easy ones

Dhuhr begins just after the sun passes its highest point in the sky. Maghrib begins at sunset. Both can be worked out from your location and the date alone, so every method agrees on them, and two good apps rarely differ by more than a minute.

Fajr and Isha depend on an angle

True dawn, when Fajr begins, comes while the sun is still well below the horizon. The same is true of the end of twilight, when Isha begins. A calculation method says how far below the horizon the sun must be, measured in degrees. A bigger angle means an earlier Fajr and a later Isha.

Three degrees sounds small, but the sun moves slowly near the horizon. Between 15° and 18° there can be twenty minutes or more, and further from the equator the gap grows, especially in summer.

Asr: one shadow or two

The Shafi’i, Maliki and Hanbali schools start Asr when an object’s shadow is as long as the object itself, plus the short shadow it had at noon. The Hanafi school waits until the shadow is twice the object’s length. So the Hanafi Asr comes later, often by close to an hour. Neither is a mistake; it is a difference of school, and apps let you pick yours.

When does Isha end?

Isha’s time is long, but scholars describe a preferred part of it. In Sahih Muslim (612) the Prophet ﷺ is reported to have said that the time of Isha lasts until the middle of the night. Many people take “the middle of the night” to mean Islamic midnight: halfway between Maghrib and the next Fajr, not 12:00 on the clock. In summer that can come well before midnight.

So which times are right?

The ones your community follows. When two apps disagree, check three things:

1. The method. Most regions have a convention; your local masjid’s timetable will show it.
2. The Asr school. Hanafi or the others.
3. Your exact location. A city search can land a few kilometres off, and that moves every time a little.

Match those to your masjid and the times will line up. After that, the hard part is no longer knowing when to pray. It is praying when the time comes, and that is a habit worth building one prayer at a time.