How Prayer Times Are Calculated Worldwide: A Complete Guide

Prayer times change from one city to the next and from one day to the next — and there is a precise astronomical reason why. Each of the five daily prayers is tied to a specific position of the sun in the sky, so the exact clock time depends on your latitude, your longitude, the date, and the calculation convention followed in your region. This guide explains, in plain language, exactly how prayer times are calculated around the world.

Prayer Times Follow the Sun, Not the Clock

The times of the five daily prayers were defined by the Prophet Muhammad ﷺ in relation to observable moments in the sun's daily journey — dawn, midday, the afternoon, sunset, and nightfall. Because the sun rises and sets at different moments depending on where you stand on Earth and what day of the year it is, prayer times can never be fixed to the clock. They are recalculated for every location and every date.

To build a daily timetable, astronomers and prayer-time engines work with a set of reference moments in the day:

• Fajr — when the first light of dawn appears in the sky.
• Sunrise (Shuruq) — when the upper edge of the sun appears on the horizon; it marks the end of the Fajr period.
• Dhuhr — just after the sun crosses its highest point (the meridian) at midday.
• Asr — when an object's shadow reaches a defined multiple of its height.
• Sunset (Maghrib) — when the sun fully disappears below the horizon.
• Isha — when the last glow of twilight leaves the sky and full darkness sets in.
• Midnight — the midpoint of the night, used to bound the Isha period.

The Two Astronomical Values Behind Every Timetable

Two continuously changing values drive the entire calculation.

The Equation of Time is the difference between time shown by a sundial and time shown by a clock. Because the Earth's orbit is elliptical and its axis is tilted, the sun appears to run slightly "fast" or "slow" across the year — up to about 16 minutes ahead in early November and about 14 minutes behind in mid-February. Prayer-time software corrects for this every single day.

The declination of the sun is the angle between the sun's rays and the plane of the equator. It shifts throughout the year as the seasons change and determines how high the sun climbs at your latitude. Together, these two values — obtainable to within about one arcminute using standard astronomical formulas, such as those published by the U.S. Naval Observatory — let a computer pinpoint the sun's position for any date and place.

Turning the Sun's Position into Clock Times

Once the sun's position is known, each prayer time follows from a clear rule.

Dhuhr is the simplest: it is solar noon — the instant the sun crosses the local meridian — plus a small precautionary margin. It depends on your longitude, your time zone and the equation of time.

Sunrise and sunset are calculated as the moments the sun sits about 0.833° below the horizon. That fraction of a degree accounts for atmospheric refraction, which lifts the sun's image slightly, and for the width of the sun's disc.

Fajr and Isha are the "twilight" prayers. Fajr begins when the sun is a set number of degrees below the horizon before sunrise; Isha begins when the sun is a set number of degrees below the horizon after sunset. This "twilight angle" is exactly where the world's authorities differ.

Why Fajr and Isha Differ From Country to Country

There is broad agreement on Dhuhr, Asr, sunrise and sunset. The visible differences between prayer apps almost always come from the Fajr and Isha twilight angles, which are set by respected regional authorities. The most widely used conventions are:

Convention	Fajr angle	Isha angle
Muslim World League	18°	17°
Islamic Society of North America (ISNA)	15°	15°
Egyptian General Authority of Survey	19.5°	17.5°
Umm al-Qura University, Makkah	18.5°	90 min after Maghrib (120 in Ramadan)
University of Islamic Sciences, Karachi	18°	18°
Institute of Geophysics, University of Tehran	17.7°	14°

This is why the same city can show a Fajr time that differs by 20–30 minutes between two trustworthy sources. Neither is "wrong" — they simply follow different conventions. Many countries adopt an official method: much of the Arab world and Europe uses the Muslim World League angles, North America commonly uses ISNA, Saudi Arabia uses Umm al-Qura, and Pakistan, India and Bangladesh often use the Karachi convention.

Asr: One Prayer, Two Valid Times

Asr is defined by shadow length rather than a twilight angle, and here the schools of Islamic law differ. The majority — the Shafi'i, Maliki, Hanbali and Ja'fari schools — hold that Asr begins when an object's shadow equals its own height, in addition to the shadow it already cast at noon. The Hanafi school holds that Asr begins when the shadow reaches twice the object's height, plus the noon shadow. In practice this makes the Hanafi Asr later by roughly 30–60 minutes, depending on the season and latitude. A good prayer-time engine lets you choose the school that applies to you.

Maghrib and the Sunni–Shia Nuance

For the majority (Sunni) view, Maghrib begins the moment the sun has fully set, usually with a precautionary delay of one to three minutes. The dominant Shia view waits until the redness of dusk has passed overhead, often modelled with a small twilight angle of about 4° below the horizon. This is a further reason why two timetables may not match to the minute.

The High-Latitude Problem

Beyond roughly 48° of latitude, there are weeks each year when twilight never fully disappears — the sun simply does not dip far enough below the horizon. In these periods the standard Fajr and Isha angles produce no result, so special rules are applied. Three common solutions are:

• Middle of the Night — the span from sunset to sunrise is halved, and Fajr and Isha are anchored to that midpoint.
• One-Seventh of the Night — the night is divided into seven parts; Isha begins after the first seventh and Fajr at the start of the last seventh.
• Angle-Based Method — the night is divided in proportion to the chosen twilight angle, giving a smoother, intermediate result.

Communities in northern Europe, Canada and Russia rely on one of these approaches during the long summer days.

How AZAN.NET Calculates Your Times

AZAN.NET applies the same peer-reviewed astronomical formulas described above, computing the sun's declination and the equation of time for your exact coordinates and date. For each country we apply the calculation convention most widely accepted there, while the underlying mathematics — Dhuhr from solar noon, sunrise and sunset at 0.833°, Fajr and Isha from the regional twilight angle, and Asr from your chosen school — stays consistent worldwide. The result is a timetable that is both astronomically accurate and faithful to local practice.

Frequently Asked Questions

Why do two apps show different prayer times for the same city?

Almost always because they use different Fajr and Isha twilight angles, or a different Asr school. Both can be valid; they simply follow different conventions.

Which calculation method should I use?

Use the one adopted by the recognised religious authority in your country or by your local mosque, so your times match the community around you.

Do prayer times change every day?

Yes. Because the sun's position shifts a little each day, every prayer time moves by a minute or two from one day to the next, following the seasons.