Days permissible for voluntary Sawm

Q: I am a twenty-seven-year-old Saudi man. I went to prison and I began to worship Allah. I observe Sawm (Fast) on Monday and Thursday of every week; on three days of every month; the whole month of Rajab; nine days of Dhul-Hijjah; the Day of `Ashura’ (10th of Muharram) and a day before and after it; six days of Shawwal; and mid-Sha‘ban. It is claimed that Sawm should be observed in Ramadan only, and the rest is a Bid‘ah (innovation in religion), and there is no Sahih (authentic) Hadith that proves them. But I found a Sahih Hadith which states this in the book entitled Tanbih Al-Ghafilin by Shaykh Abu Al-Layth Al-Samarqandy. Please advise whether Sawm on these days is really a Bid‘ah, given that my colleagues in prison say so.

A: Sawm on Mondays and Thursdays, three days of every month (13th, 14th, and 15th of every Hijri month), the ninth of Dhul-Hijjah, the tenth of Muharram, in addition to a day before or after it, and six days of Shawwal, every year, all this is Sunnah (supererogatory acts of worship following the example of the Prophet) established by authority of Sahih Hadiths. (Part No. 10; Page No. 385) It is also an act of Sunnah to observe Sawm for the first half of Sha‘ban, or the whole of this month, or most of it. As for singling out the day of mid-Sha‘ban for Sawm, it is Makruh (disliked) and groundless. May Allah grant you more success. Singling out the month of Rajab for Sawm is also Makruh. However, if a person observes Sawm on some of its days and breaks Sawm on other days, there is nothing wrong with this. May Allah double your reward and accept your Tawbah (repentance to Allah).May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family and Companions.