Yawm al-Shakk (the day of doubt, fiqh)

يَوم الشك

Yawm al-shakk is a juristic term for the thirtieth of Sha'ban when the sighting of Ramadan's crescent is not legally established; it is so named because it may be the first of Ramadan. The schools differ on its definition and on the ruling of fasting it: the Hanafis allow only supererogatory fasting with a distinction between the select and the common people, the Malikis bar a precautionary fast for Ramadan, the Shafi'is on the sound view do not permit it without a reason, and the Hanbalis dislike a fast intended precautionarily as Ramadan. ^{1 2 3}