Difference Sehri & Fajar
Sehri ends when Fajr time actually begins, not at jamaat time and not based on when the azan finishes.The Qur’an says eat and drink until the white thread of dawn becomes distinct from the black thread — meaning until true dawn begins. If the app shows Fajr at 5:46 AM, that means true dawn begins at 5:46, so you can eat and drink until that time. Sometimes people stop 10–15 minutes earlier as a precaution, but that is a personal safety buffer — it is not a religious requirement. Also, jamaat time is usually later than Fajr start time, not earlier. So if someone says the time shown is for jamaat, that would normally be incorrect because jamaat happens after Fajr begins. Muslim apps calculate the astronomical Fajr time based on selected calculation methods. They are showing the actual beginning of Fajr, which is when fasting starts. So unless your local mosque is giving the azan earlier than Fajr (which should not happen), sehri should end at the Fajr time shown in the app.