Why Do Prayer Times Differ? Diyanet, Fazilet and Süleymaniye

For the same day and the same city, two calendars can show Fajr more than an hour apart. This is not an error: all calendars calculate the sun’s position in the sky using the same astronomy, but define the moment a prayer time “begins” differently.

Same day, three calendars

Istanbul, 21 June 2027, the longest day of the year:

In winter, the gap shrinks: on 15 January 2027, Fajr is 06:50 in Türkiye’s Presidency of Religious Affairs (Diyanet), 06:33 in Fazilet, and 07:39 in Süleymaniye.

The Diyanet column is calculated using the parameters published by Diyanet. The Fazilet and Süleymaniye columns are calculations calibrated by Zeen according to the tables published by these calendars; they may differ by one or two minutes from the calendars’ own tables.

What creates the difference?

Fajr and Isha angles

Fajr and Isha are determined by how far the sun is below the horizon. Diyanet uses the moment the sun approaches within 18 degrees of the horizon for Fajr, and the moment it drops 17 degrees below for Isha. As the angle increases, Fajr shifts earlier and Isha shifts later.

The calculation that best matches the Fazilet Calendar tables corresponds to 19 degrees for Fajr; therefore, its Fajr is earlier than Diyanet’s. The Süleymaniye Foundation calendar, based on an interpretation that treats morning and evening twilight as symmetrical, uses approximately 9 degrees for both times; as a result, its Fajr is about an hour later and its Isha is about an hour earlier.

Precautionary margin (Temkin)

Temkin is a precautionary margin added to the calculation to ensure that every point within a city has entered the prayer time. Diyanet applies a 7-minute margin at sunrise and sunset, 5 minutes at Dhuhr, and 4 minutes at Asr; there is no margin for Fajr and Isha. Because calendars choose these margins differently, Sunrise, Dhuhr, Asr, and Maghrib times also diverge by a few minutes. Many international methods do not use a precautionary margin at all.

Asr calculation

Asr is calculated by the moment an object’s shadow reaches a certain length. Calendars in Türkiye show the moment when the shadow equals the object’s height (asr-ı evvel). In calendars that show the moment when the shadow is twice the object’s height (asr-ı sânî), Asr is later: in Istanbul, this difference reaches 38 minutes in winter and up to 74 minutes in summer.

Location

In Türkiye, Diyanet publishes prayer times district by district. In a large city, a difference of one or two minutes between the center and an outer district is normal. As you move further from the equator and pass beyond the 45th parallel, twilight in summer can last throughout the night; there, calendars apply special rules and the differences grow even larger.

Which one to use?

Which calendar to follow is not a question of calculation, but a matter of preference and jurisprudential evaluation. Zeen does not take sides on this issue: it calculates each calendar according to its own method, and you choose the time source. For views on this matter, you can consult your local religious authority.

You can view today’s times for your city on the prayer times page.