Fathwa, - Menstruation: missed prayers relying on one’s habit

Question:
I normally have my period for four days. On the fourth day I normally
bleed at night but I am clean in the day. If I refrained from prayers
of isha and taraweeh thinkingthat previously this is how my cycle
works but the next day I find that I was wrong should I make up those
prayers I missed?
Answer:
Assalamu alaykum
If one�s menstrual bleeding stops before the end of a particular
prayer time leaving one with enough time to perform the ritual bath
and commence that prayer then one is responsible for that particular
prayer. (Radd al-Muhtar) Should one not perform that prayer then one
must make it up. One must therefore make up the isha prayer that was
missed as well as the witr prayer. Sunnaprayers are not made up after
their time has elapsed so one need not worry about making up for the
missed taraweeh prayers.
It is a major sin to miss an obligatory prayer intentionally. One must
learn the fiqh of menstruation so as to avoid falling into this sin.
May Allah increase us in knowledge of that whichbenefits us.