Answered by Shaykh Ilyas Patel
Which are the six days of the year, when fasting it prohibited? Mufti Taqi Usmani mentions it in the article on rajabhttp://www.albalagh.net/general/rajab.shtml Please suggest.
Answer:
In the Name of Allah, Most Merciful and Compassionate
The six days are the two Eids, Eid al-Fitr and Eid al Adha, three days of Tashriq in the month of Zul Hijja 11th, 12th and 13th and Day of Doubt, the day after the 29th of Shaban as neither Shaban nor Ramadhan is certain.
(Mufti A. H. Elias, The Book of Fasting and I’tikaf pg 14)
And Allah knows best
– Ilyas