Islam and the Quran

Fajr time in Istanbul

18 degrees is the basis for the calendar of The Presidency of Religious Affairs. However this is complied in Ramadans only. Out of Ramadan, fajr time adhan is usually recited 1 hour before fajr prayer. Following links provide further information on this topic:

Fasting Prolonged At Least Forty Minutes in Turkey

Does the 40-Minute Fajr Time Mistake in Calendars Persist This Year?

Dear brothers and sisters at Islam & Quran
I would like to ask about fajr praying times in Istanbul and the calculation method used.
I recently vistied Istanbul and noted that the fajr praying occurs later than expected or calculated by a software I use in my Iphone.
My phone uses a sun inclination degree of 16 to calculate alfajr praying but I didn’t hear the Azan until 15 minutes after my Iphone announcement.
This occured over few nights.
Could you advcie me about this and also what sun inclination / depression used in Istanbul.