The Friday prayer replaces the dhuhr prayer on Fridays; for jurists other than the Hanbalis its time is the time of dhuhr (TDV Encyclopedia of Islam, “Cuma”). Dhuhr starts once the sun has passed its highest point and lasts until asr begins, which Diyanet’s calendar places where a shadow equals its object’s length. Through the year the dhuhr time moves by about half an hour because of the equation of time; the gap between provinces comes from longitude and stays the same all year, 14.44° × 4 min ≈ 58 minutes between Istanbul (28.97° E) and Van (43.42° E).
FormulaDhuhr = 12:00 − 4 min × (longitude − 45°) − equation of time + marginTurkish time is UTC+3, the time of the 45° meridian; every degree further west is 4 minutes later. The equation of time corrects the sun’s uneven pace through the year (±16 minutes). Diyanet starts dhuhr 5 minutes after the sun crosses the meridian.
Frequently asked questions
What time does the Friday prayer start?
The tool gives the time dhuhr begins; the Friday call to prayer is read once it has begun. The times of the sermon and the obligatory prayer vary from mosque to mosque; ask your mosque or the provincial mufti’s office for the exact time.
Does it match Diyanet’s time?
It uses Diyanet’s method (5 minutes’ margin at dhuhr); in HerHesap’s check against the 2026–2027 times for all 81 provincial centres on namazvakitleri.diyanet.gov.tr it is within 1 minute.