My father died when I was 5 and I want to know if I can fast for the days that he might have not fasted, but I don't know the exact number of days! So, can I fast them? Also, I had an uncle who used to take care of us, like a father to us, but he died 3 years ago. I want to know if I can fast for him even though I don't know the number of days? When I say Du'a can I say forgive my father(s) even though he's my uncle but it's hard to say uncle!

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

The preponderant opinion of Muslim scholars is that it is desirable for a Wali (guardian) of a dead person to fast on his behalf. If one fasts on behalf of a dead person, the fast is valid and the dead person becomes free from his obligation.

‘Aa’ishah narrated that the Prophet said: “If one dies and has some fasts to make up, then his guardian should fast on his behalf.” [Al-Bukhari and Muslim]

In the above Hadeeth, Wali means any relative of a dead person according to the preponderant opinion of the scholars. According to some scholars it is allowed for any person to fast on behalf of a dead person. They believe that the Prophet pointed out Wali since he is the most deserving person to fast on behalf of his dead person. It does not mean that no one else could fast on behalf of a deceased person except his Wali.

Therefore, you may fast on behalf of your father and uncle the days they had failed to fast. If you are not sure of the exact number of days, then you should fast the most probable number of days they missed. It is better to take the safe estimate. You may say: O Allah! Forgive my fathers, using the plural expression. Allah Says (what means): {Or were you witnesses when death approached Jacob, when he said to his sons, "What will you worship after me?" They said, "We will worship your God and the God of your fathers, Abraham and Ishmael and Isaac - one God. And we are Muslims [in submission] to Him."} [Quran 2: 133]

It is known that Ismael was the uncle of Ya’qoob and not his father, since he was the brother of Is-Haaq.

Allah knows best.