Topic #4: Which is the appropriate or best time for offering Tahajjud Salah (namaaz)?
The time for Tahajjud (Qiyam-ul-lail) starts after Salat-ul-Isha and remains till the start of Fajr.
One can pray Tahajjud salah any time after Salat-ul-isha, but the best time for praying Tahajjud is the last part of the night which is somewhere between 15-20 minutes before the start of Fajr.
Praying Tahajjud in that part of the night is a great act in Islam and a highly effective way of getting Allah's Qurb (closeness). One should make lots and lots of duas at this time.
May Allah bless us all with the beauty of salah and may he help us pray Tahajjud salah. Aameen.
And Allah knows best!