Reference: Fataawa Ramadhaan – Volume 2, Page 723, Fatwa No.730
Fataawa as-Siyaam – Page 101
Question: What is the day of doubt and is it permissible to fast on that day?
Response: The day of doubt is the 30th day of Sha’baan, and it is not permissible to fast on this day as it has been related by ‘Ammaar ibn Yaasir رضي الله عنه who said:
«Whoever fasts on the day concerning which there is doubt has disobeyed Abul-Qaasim ﷺ», [transmitted by at-Tirmidhee and an-Nasaa.ee]
