Re: how long after azan can you pray till
Azan has nothing to do wit the time of the prayer as Azan can be called even after the time entered and sometimes by mistake, even before.
Fajar can be prayed till 7-8 minutes before the sunrise.
Every other prayer is valid if you can say your first Takbeer and start Qiyaam just before the time of the next prayer enters. So if Maghrib is at 7:00 PM and you start your Asr at 5:59:30 (and carried it inside the Maghrib Prayer), its is considered a valid prayer.