Performance of prayer at their due times is referred to as "ada" ; while performing them after their due times is called "Qadha".

Only the obligpart of the missed daily prayers including the Old-Numbered Prayers (Salat al Witr) is performed. That is the sunnah parts of the scheduled-time prayers are not performed. However, the sunnah rakats of the missed Morning Prayer (Salat al Fajr) are performed along with the obligatory rakats up until the midday of the very same day.

Qadha prayers can be performed at any time of the day other day the dissapproved times. Not performing the prayer at their due times deliberately, without any real excuse and missing them is major sin. Nevertheless, although our indeptedness towards Allah is removed by the late performance of missed prayers, the sin of the late performance remains. For this resaon, we must not only perform the missed prayers, but we also must ask Allah forgiveness.