The best of the days of the week on which to fast is Monday and Thursday.
My sister undertook a vow to fast on Friday, so is it permissible for her to fulfil her vow or not? And if it is not permissible, is she then required to make an expiation?
Is it permissible to make up missed fasts of Ramadhaan on Thursday and Friday or not?
My father would never miss fasting [every] Monday and Thursday, and the three full moon days.