Bohra prayer times: how each window is calculated

Short answer: the span from zawaal (solar noon) to sunset is divided into three. Zohar owns the first third, Asr the second. Maghrib and Isha stay ada until nisf al-layl, which is zawaal plus twelve hours. Isha begins at the red afterglow, 15° of sun depression. Fajr begins at whichever comes first: 75 minutes before sunrise, or 12° dawn.

This is a calculation, not a ruling. Namaaz Tracker computes these times from the rule described on this page. Where it disagrees with the timetable published by your own jamaat, follow your jamaat. The purpose of writing the rule down is so you can check ours against theirs, not so it replaces theirs.

The rule, prayer by prayer

Prayer	Starts	Still ada until
Fajr (Sihori)	min(sunrise − 75 min, 12° dawn)	Sunrise
Zohar	Zawaal (solar noon)	Zawaal + ⅓ of (sunset − zawaal)
Asr	Where Zohar ends	Zawaal + ⅔ of (sunset − zawaal)
Maghrib	Sunset	Nisf al-layl = zawaal + 12h
Isha	Shafaq ahmar, 15° depression	Nisf al-layl = zawaal + 12h

Both ends of the Zohar and Asr windows carry a two-minute ihtiyat margin. Drop it and the printed end times run one to three minutes past the published ones.

Where this differs from a general-purpose prayer app

Most prayer-time libraries ship madhab defaults that do not match the Fatimid reckoning. Three differences matter, and each one moves a real boundary:

• Asr starts where Zohar ends, not at the shadow length. The common Shafi rule puts Asr at the moment an object's shadow equals its own length plus the noon shadow. In Mumbai on 12 August that is about 4:00 PM. The thirds rule puts it at about 2:50 PM — over an hour earlier. Anyone praying Zohar at 3:30 PM on the shadow rule has, on this reckoning, already missed the window.
• Maghrib does not end fifteen minutes after sunset. Some Bohra tables print a short "Maghrib end". That is the makhsus stretch, during which Maghrib has the time to itself; after it, Maghrib and Isha share the time. Both stay ada until nisf al-layl. It is not the ada boundary.
• Isha begins at 15°, not 17°. The 15° figure is the red afterglow, shafaq ahmar. The Muslim World League's 17° is the white glow and arrives roughly ten minutes later.

Fajr: why no single angle works

This is the part that is usually got wrong, including by us at first. A flat 75 minutes before sunrise reproduces the published Sihori time exactly in Mumbai, Karachi, Colombo, Nairobi, Sydney and Toronto, in every season sampled. It only fails where twilight outlasts it — London all year, Toronto in June — and there the published tables follow the 12° dawn instead.

So the rule is min(sunrise − 75 min, 12° dawn). No single depression angle expresses it: the same published tables imply about 19° at Nairobi and about 12° at London. Fitting one angle to both is what makes a general prayer app show Fajr an hour early in London.

Checked against 16 published rows across those cities, the worst disagreement is four minutes.

Note the separate "Fajr Azaan" row some tables print is a recommended time, not the edge of the window.

Nothing here marks a prayer qaza for you

Namaaz Tracker never sets a status by itself. The window printed on each tile is the app's whole statement about when a prayer is still ada — you decide what to record, always. That is also why the rule is written out here rather than left inside the code: if the window is wrong, it is wrong about something that matters.