Why there is more than one "correct" time
All prayer-time methods agree on the astronomy: the five prayers are tied to the sun. They differ only on one hard-to-measure moment — exactly how far the sun must sit below the horizon for dawn (Fajr) to begin and for night (Isha) to fall. Because twilight fades gradually, respected scholarly bodies settled on slightly different angles, and those small differences produce the few-minute gaps you see between apps. None is "wrong"; each reflects a recognised convention.
Muslim World League (MWL)
The MWL method uses an 18° angle for Fajr and 17° for Isha. It is one of the most widely adopted standards worldwide and is a sensible default for much of Europe, Central Asia, and parts of Africa. Its moderate angles give times that sit comfortably between the earlier and later conventions.
Islamic Society of North America (ISNA)
ISNA uses a shallower 15° angle for both Fajr and Isha. Shallower angles mean the sun does not have to drop as far, so Fajr arrives a little later and Isha a little earlier than with MWL. ISNA is the common choice across the United States and Canada, partly because the higher latitudes there make the steeper 18° angle harder to reach for much of the year.
Umm al-Qura (Makkah)
The Umm al-Qura method, maintained from Makkah, sets Fajr at 18.5°. Its distinctive feature is Isha: instead of an angle, it uses a fixed interval of 90 minutes after Maghrib (120 minutes during Ramadan). This is the standard across Saudi Arabia and is widely followed in the Gulf.
University of Islamic Sciences, Karachi
The Karachi method uses 18° for both Fajr and Isha. Symmetric and straightforward, it is the standard across Pakistan, India, Bangladesh, Afghanistan and much of South Asia.
The Asr question, separately
Independent of the Fajr/Isha method, Asr has two valid timings. The Standard opinion (Maliki, Shafi'i, Hanbali) begins Asr when an object's shadow equals its own length; the Hanafi opinion begins it when the shadow is twice the object's length, which falls noticeably later. A city can therefore show two different Asr times even under the same Fajr/Isha method.
Which method should you use?
The most practical rule is to match the convention used by mosques in your country, so your prayers line up with the local congregation. SalatWaqt applies the method commonly followed in each country by default, which is why our times generally agree with your nearest masjid. If you prefer a specific method or the Hanafi Asr, you can follow the timing your local scholars advise — the underlying astronomy on this site is the same either way.
A worked example: the same evening, four methods
Imagine a city where Maghrib (sunset) falls at 6:45 pm. Under ISNA's shallow 15° angle, the sky is still considered "lit" for a shorter time, so Isha might be reckoned around 8:00 pm. Under MWL's 17°, the sun has to sink a little further, pushing Isha closer to 8:10 pm. Under the symmetric 18° of Karachi, it is later still. And under Umm al-Qura there is no angle at all for Isha — it is simply 90 minutes after Maghrib, i.e. 8:15 pm. Four respected methods, the same sunset, and a spread of roughly fifteen minutes for Isha. None has miscalculated; they have each answered "when has night truly fallen?" with a slightly different, defensible definition.
Frequently asked questions
Does the method change Dhuhr, Asr or Maghrib? The angle methods affect only Fajr and Isha, because those depend on twilight. Dhuhr (solar noon) and Maghrib (sunset) are fixed astronomical events that every method shares. Asr varies only by the separate Standard/Hanafi choice.
Is one method "more authentic" than the others? No. Each is endorsed by recognised scholarly authorities for the regions that use it. The differences come from how cautiously twilight is defined, not from anyone being mistaken.
What about extreme northern or southern cities? At high latitudes the sun may never reach the chosen angle in summer, so a "high-latitude rule" is layered on top of the base method to produce sensible Fajr and Isha times. This is covered in our article on fasting hours by latitude.
The bottom line
Differences between methods are a matter of a few minutes and reflect legitimate scholarly conventions, not errors. Understanding the angle behind each one makes it clear why your phone, your mosque and a printed timetable can each be slightly different — and all still correct. Pick the method your local community follows, set it once, and trust it.