What is the ruling regarding the timing of the intention for a voluntary fast within the daytime?
General Chapter
Al-Mughni
Book of Fasting
Primary text
Any time during the day for forming the intention suffices, whether before or after Al-Zawal (midday zenith). This is the apparent position of Ahmad and Al-Kharqi, and is supported by the statement of Ibn Mas'ud: one is allowed to fast if one abstains, provided one has not eaten or drunk. Sa'id ibn al-Musayyib affirmed this when asked by a man who abstained until noon or the afternoon. The evidence is that the intention was made during a part of the day, which is analogous to making the intention at the beginning of the day. Since the entire night is a time for the intention of the obligatory fast, the entire day is a time for the intention of the voluntary fast.
Supporting text
Al-Qadi, in 'Al-Muharrar,' prefers that intention made after Al-Zawal is invalid. This is the madhhab of Abu Hanifa and the well-known view of Al-Shafi'i, based on the reasoning that the majority of the day has passed without the intention, unlike one who intends before Al-Zawal and has achieved the majority of the act of worship.