When must one begin I'tikaf for the entire month of Ramadan if vowed?
General Chapter
Al-Mughni
Book of I'tikaf
Primary text
One who vows the entire month of Ramadan for I'tikaf must enter the mosque before sunset on the first night to fulfill the complete month. This is because the month begins at sunset, as indicated by the fact that debts suspended on the month's arrival become due then. That which is necessary to complete the obligation is itself obligatory, like observing a part of the night along with the day for fasting. The fasting itself is confined to the daytime, so nothing of the night enters its beginning except out of necessity, unlike I'tikaf.
Supporting text
A differing view suggests entering after the morning prayer (Fajr) based on the Hadith that the Prophet (PBUH) prayed Fajr then entered his place of seclusion, and the verse commanding fasting from the appearance of the month (Quran 2:185) implies fasting starts at dawn. However, this opinion is considered not followed by any jurist according to Ibn Abd al-Barr concerning vowed I'tikaf. If one vows I'tikaf for a specific day, entering before dawn and exiting after sunset is required.