The Days on Which Fasting Is Prohibited

Question: What are the days on which fasting is disliked?

Answer: The days on which fasting is prohibited include Friday, where it is not permissible to fast on Friday alone as a voluntary act; because the Messenger of Allah (peace and blessings be upon him) prohibited that.
Likewise, one should not single out Saturday for voluntary fasting, but if one fasts on Friday along with Saturday or along with Thursday, there is no harm, as the hadiths from the Messenger of Allah (peace and blessings be upon him) indicate.
Similarly, fasting on the Day of 'Id al-Fitr is prohibited, and that is forbidden. Likewise, the Day of Sacrifice and all the days of Tashriq are not to be fasted; because the Messenger of Allah (peace and blessings be upon him) prohibited that, except that there is evidence indicating the permissibility of fasting on the days of Tashriq specifically for the sacrifice of Tamattu' and Qiran for those who cannot afford the sacrificial animal; as established in al-Bukhari from 'Aishah (may Allah be pleased with her) and Ibn 'Umar (may Allah be pleased with them both), who said: .
As for fasting them voluntarily or for other reasons, it is not permissible, just like the Day of 'Id. Likewise, the thirtieth of Sha'ban, if the sighting of the crescent moon is not confirmed, is a day of doubt on which fasting is not permissible according to the stronger of the two opinions of the scholars, whether it is clear or cloudy; due to the authentic hadiths indicating the prohibition of that. And success is from Allah.