Section

They differed over fasting on the day of obscured skies: when clouds or dust haze obstruct the view of the new crescent on the night preceding the thirtieth of Sha‘bān.

Some held that one must fast that day as a precaution, intending it as a fast of Ramadan. This is the position reported from Ahmad that most of his later followers adopted and attributed to most of their predecessors. They based this on their interpretation of the hadith and on the premise that Sha‘bān usually has twenty-nine days. The crescent is therefore more likely to have appeared, as is usually the case, and fasting becomes obligatory on the basis of predominant probability.

Another group held that it is not permissible to fast that day as part of Ramadan. This is a position reported from Ahmad and adopted by some of his followers, including Ibn ‘Aqīl and al-Halwānī. It is also the view of Abū Hanīfah, Mālik and al-Shāfi‘ī. They relied on the relevant hadiths and on the principle that an obligation cannot be established by doubt.

There is a third view: that it is permissible to fast that day as part of Ramadan, and it is permissible