Why times differ between calendars
Dhuhr and Maghrib follow the sun, so everyone agrees on them. Fajr and Isha depend on the angle of the sun below the horizon, and each authority uses a different angle, so they can differ by several minutes, or more in the far north. That is why you can choose the method.
For Asr, most schools take the moment a shadow equals the object’s length; the Hanafi school takes twice its length, so Hanafi Asr is later.
Far north: Sweden, Norway, the UK, Canada
In summer the sun barely sets in northern cities, so the astronomical signs of Fajr and Isha may not appear at all. The tool then applies the recommended high-latitude rule. Mosques in these cities sometimes publish their own calendar: if yours differs, follow your mosque.
Frequently asked questions
Which method should I choose?
The one used by the mosque or Islamic centre near you, so you pray with the congregation. Many European mosques use the Muslim World League; in North America ISNA is common.
Is daylight saving time included?
Yes. Times are shown in the city’s local time, including summer time.
Is my location saved?
No. If you use your location, it stays in your browser and is used only for the calculation.
How accurate are the times?
They are calculated astronomically for the city centre or your exact position; within a city the difference is usually a minute or two.
Sources
Times are calculated astronomically; follow your mosque’s calendar when it differs. Disclaimer.