Fasting: Unlawful Fasts
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 1707
Fasting on Eid al-Fiṭr[1] and Eid al-Aḍḥā[2] is unlawful. Furthermore, if one does not know whether it is the last day of Shaʿbān or the first day of the month of Ramadan and fasts with the intention of it being the first day of the month of Ramadan, it is unlawful.
-Ayatullah Sistani, Practical Laws of Islam, Fasting (Sawm)
1
The 1st of Shawwāl.
2
The 10th Dhū al-Ḥijjah.