A: The Jurists have two opinions with respect to a Nafl (optional) fast on Friday. Some are of the opinion that fasting on a Friday independently is permissible, without any objection. Some Ulama feel one should not fast on a Friday alone, rather a fast should be kept before or after as well.
We thus deduce that one may keep an optional or Qadha fast on Friday.
And Allah Ta'ala Knows Best
Shafiq Jakhura (Mufti) M.D. Mangera (Mufti)
Fatwa Dept. Fatwa Dept.