Prayer times
ZohaNur computes the five daily prayers on your device using astronomical formulas, so they work with no connection at all.
ZohaNur calculates prayer times on your phone. It does not fetch them from a server. Given your coordinates, the date, and a calculation method, the app solves the sun's position directly — which means times are available on a flight, in a village with no signal, and for any date in the past or future.
How the times are derived#
Each prayer is defined by an observable position of the sun.
| Prayer | Defined by |
|---|---|
| Fajr | The sun reaching a set angle below the horizon before sunrise |
| Dhuhr | The sun passing the meridian, just after true noon |
| Asr | An object's shadow reaching a set multiple of its own length |
| Maghrib | Sunset |
| Isha | The sun reaching a set angle below the horizon after sunset |
The app computes the sun's declination and the equation of time for the date, then solves the hour angle for each condition at your latitude. Dhuhr includes a small allowance after true midday so that the prayer is not offered at the exact moment of the sun's zenith.
The two values that vary between authorities are the fajr and isha angles and the asr shadow ratio. Those are what the fourteen calculation methods encode.
The basis for the times#
Indeed, prayer has been decreed upon the believers a decree of specified times.
— Surah an-Nisa 4:103
The specific boundaries come from the Sunnah, most directly from the narration in which Jibril led the Prophet ﷺ in prayer on two consecutive days — at the beginning of each window on the first day and at the end on the second — and then said that the time is between these two. That narration is the basis for treating each prayer as a window rather than an instant, and it is why the app shows the time remaining until the next prayer rather than only the entry time.
Accuracy, and when to disagree with the app#
The astronomy is precise. What is not precise is which convention your community follows, and that is a matter of scholarly and local decision rather than calculation.
Where ZohaNur disagrees with your local masjid, follow your local masjid. The app is a tool for when you cannot consult one, not a replacement for it. If the difference is more than a couple of minutes, the calculation method setting is almost certainly the cause.
Other things that shift the times legitimately:
- Elevation. At altitude the sun sets later than at sea level.
- Your position within a time zone. Cities sharing a zone can differ by many minutes of true solar time.
- Extreme latitudes, where twilight may not end at all in summer. See high latitude rules.
What is stored#
Your coordinates are saved on your device so that times still work when location is unavailable. They are not transmitted to us. See how your location is found and the privacy policy.
If alerts are not arriving#
The times being correct and the notification arriving are separate problems, and the second is usually Android's battery management. Troubleshooting alerts →