Days on which Supererogatory Fasting is Recommende

1- Six days in the month of Shawwal (after the month of Ramadan)
The Prophet ﷺsaid �Whosoever fasts the month of Ramadan and thereafter follows it up with six days of fasting in Shawwal, it will be recorded (altogether) for him as a complete year of fasting.� [ Source: Muslim.]


It is the same if he does it consecutively or spreads it over the entire month.


2- First nine days of Dhul Hijjah (the twelfth month of the Islamic calendar)
The Prophet ﷺ said : �There is no other day in which good deeds performed are so pleasing to Allah than these days (i.e. the first ten days of the twelfth month). The companions inquired: �What about jihad (fighting) in the cause of Allah?� The Prophet said: �Not even jihad in the cause of Allah (is up to its rewards), except for a man who went out in the cause of Allah with his life and wealth and did not return with anything of either (of them).� [ Source: Bukhari.]


However, the most important of these days is the day of �Arafah, for those not performing the pilgrimage. The day of �Arafah is the ninth day of the twelfth month of the Islamic calendar. The Prophet ﷺ said: �As for fasting on the day of �Arafah, I expect Allah Almighty will reward that by forgiving the sins of a year gone and a coming year.� [ Source: Muslim.]


3- Fasting on �Ashura
This is because the Prophet said: �And as for fasting on the day of �Ashura, I expect that Allah Almighty shall forgive the sins of the year prior to it.� [ Source: Muslim.]


The reason for fasting on this day is in accordance with what was related from the authority of �Abdullah ibn �Abbas, who said: �When the Prophet ﷺ arrived at Madinah, he found the Jews fasting on �Ashura. Then he inquired why (do they fast on that day)? They answered, �This a good day, the day Allah Almighty saved the children of Israel from their enemy, and as such Prophet Musa (peace be upon him) fasted thereafter (on that day).� Then the Prophet said: �I have more right to Musa than you.� Then he fasted and ordered the Muslims to fast on that day.� [ Source: Bukhari.] In another narration by Imam Muslim, the Prophet said, �If I remain (alive) till the next year, I shall fast the ninth day.� [ Source: Muslim.]


4- The bright days in every month
It is authenticated that Abd al-Malik ibn al-Minhal conveyed from his father that the Prophet ﷺ ordered them to fast the three �bright� days. He said, �It is [equivalent] to fasting the entire month.� [ Source: Ibn Habban.]


5- Fasting on Monday and Thursday of every week
Abu Hurayrah reported that the Prophet ﷺ said: �Deeds are reported to Allah Almighty on every Monday and Thursday; and I like that my deeds are reported while I am fasting.� [ Source: Tirmidhi.]


6- Fasting on alternative days.
The best form of supererogatory fast is the fast of Prophet Dawud (peace be upon him). He used to fast a day and take a break the next day. Abdullah ibn �Amr reported the Prophet ﷺ to have said: �The best form of fasting is the fasting of Dawud (peace be upon him); he used to fast a day and take a break on the next (day).� [ Source: An-Nasaii.]


7- Fasting in Muharram (the first month of the Islamic calendar).
On the authority of Abu Hurayrah, the Prophet ﷺ said: �The best form of fasting besides Ramadan is in the month of Allah, Al-Muharram.� [ Source: Muslim.]


8- Fasting in Sha�ban (the eighth month of the Islamic calendar)
�O Prophet of Allah! I have not seen you fast in any month as you do in Sha�ban.� The Prophet replied: �That is the month, between Rajab and Ramadan, about which many people are not conscious, and deeds are returned to the Lord of the worlds (during it). Thus I love that my deeds are returned to Allah Almighty while I am fasting.� [ Source: An-Nasaii.]


Regarding the prohibition contained in the Prophet�s ﷺ hadeeth, where he said: �When Sha�baan is half over, do not fast until Ramadan,� [ Source: Ibn Khuzaymah.] it either means that the prohibition is related to deliberately fasting only after the month is halfway over, or to joining Sha�baan with Ramadan. However, a person who continues fasting the second half of Sha�baan after fasting during the first part of the month and does not join that month with Ramadan in fasting, then there is nothing wrong with his fasting.
source: islamkingdomsawm