How to Create a Custom Calculation Method

If you’re noticing large differences between the prayer times in the app and those of your masjid, especially for Fajr and Isha times, your masjid may be using custom twilight angles to generate their prayer times.

You can create a custom calculation method in the app to try to match the times of your masjid as closely as possible, by following the steps below.

Note: Without knowing the specific angles and adjustments that your masjid is using, you will have to make a guess that matches their timetable. Also, depending on geographical location, their angles may vary throughout the year, so your custom calculation may need to be adjusted throughout the year as well.

Custom Calculation Method

In the app, go to Settings > Calculation > Method > look at the selected method (eg: ISNA) and make a note of the Fajr and Isha angles listed (eg: 15 deg. both)

After noting these angles, scroll down to the bottom of the list and select Custom.

Start by adjusting the Fajr and Isha angles to match the ones used by the calculation method you are currently using (eg: 15 degrees).

Then continue making adjustments to these angles and checking the Times screen until you’ve found the angles that render prayer times that closely match your local masjid (give or take 1-2 minutes).

Again, because Pray Watch calculates the prayer times based on your device’s GPS location, a small difference of 1-2 minutes is normal since your location is not the same as the masjid or the local council that was used to generate their times for the whole region.

For Higher Latitudes

If you live in a city that lies in a higher latitude (ie: above 48 degrees North), Fajr and Isha prayers can be difficult to perform. To account for this, you might try adjusting the Elevation rule in the settings:

*Do not change your calculation method as stated in the steps above; leave it set to your local authority.

Go to Settings > Calculation > Adjustments > Elevation rule

Try each of the options and check the Times screen to find the one that renders Fajr and Isha times that closely match your local masjid (give or take 1-2 minutes).