How late can pray Isha?
Praying Isha on time is the Sunnah. Isha is valid from the beginning time of Isha until Fajr begins.
It is recommended as the Prophet (peace be upon him) mentioned to delay Isha if you are sure that you will pray it.
“If it wouldn’t have caused hardship on my Ummah, I would have ordered them to delay Isha.” (An-Nasa`i)
However, if you are not sure and you were to sleep miss Isha then don’t delay it.
If you can pray Isha in congregation, then it is better to pray with with the congregation than to delay it and pray it alone.
It is somewhat disliked (makruh tanzihan) to delay isha past half the night, yet is still considered to be ‘on-time’ (ada’) as long as performed before the break of dawn (fajr).
Based on the answer of Shaykh Haytham Tamim in the Sunday Hadith Class April 2024