1757. Fasting is Mustahab on every day of a year except those on which
it is haraam or Makrooh to observe a fast. Some of them which have been strongly
recommended, are mentioned here:
The first and last Thursday of every month and the first Wednesday after
the 10th of a month. If a person does not observe these fasts it is Mustahab
that he gives their qadha. And if he is incapable of fasting, it is Mustahab
for him to give one mudd of food or prescribed coined silver to poor.
13th, 14th and 15th day of every month.
On all days of Rajab and Shaban or on as many days as it is possible to
fast, even though it may be one day only.
The day of Eid Nawroz.
From the 4th up to the 9th of the month of Shawwal.
The 25th and 29th day of the month of Zi qa'da.
From the 1st day to the 9th day (i.e. 'Arafa day) of the month of Zil
hajj. But if, it is not possible for one to recite the Duas of 'Arafa due to
weakness caused by fasting, it is Makrooh to fast on that day.
The auspicious day of Ghadir (18th Zil hajj).
The auspicious day of Mubahila (24th Zil hajj).
The 1st, 3rd and 7th day of Muharram.
The birthday of the Holy Prophet (17th Rabi'ul awwal).
15th day of Jumadi'ul oola.
Fasting is also recommended on 27th of Rajab - the day the Prophet (s.a.w.a.)
declared his Prophethood. If a person observes a Mustahab fast, it is not
obligatory on him to complete it. In fact, if one of his brethren-in-faith
invites him to a meal, it is Mustahab that he accepts the invitation and breaks
the fast during the day time even if it may be after Zuhr.