Is fasting obligatory based solely on sighting the new moon, or must thirty days of Sha'ban be completed if the moon is obscured?
General Chapter
Al-Mughni
Book of Fasting
Primary text
The ruling of the majority of scholars, including Abu Hanifa, Malik, and Al-Shafi'i, is that fasting is not obligatory, nor is it sufficient for Ramadan, unless the moon is sighted. If the moon is obscured, the count of Sha'ban must be completed as thirty days. This is supported by the Prophet's statement, "Fast upon seeing it, and break the fast upon seeing it, but if it is obscured to you, complete the count of Sha'ban as thirty." Additionally, the prohibition against fasting the Day of Doubt (Yawm al-Shakk) applies here, as the default state is the continuation of Sha'ban, and one cannot depart from it based on doubt. Fasting is only required upon seeing the moon, completing thirty days of Sha'ban, or if an obstruction like cloud or haze prevents sighting the moon, which itself is a point of scholarly difference.
Supporting text
A view held by 'Umar, his son, 'Amr ibn al-'As, Abu Hurayrah, Anas, Mu'awiyah, 'Aishah, and Asma' bint Abi Bakr, along with several early authorities, maintains that fasting commences upon sighting or completing thirty days of Sha'ban, and if clouds obscure the view, one should fast if the horizon is clear, or not fast if an obstruction prevents viewing, as narrated from Ibn 'Umar by Nafi'. The interpretation of "iqdaru lah" (make a tight calculation for it) is taking the count as twenty-nine days for Sha'ban, meaning the thirtieth day of Sha'ban is the last possible day before Ramadan.