Niyyah (intention) is a required condition in fasts, because the Prophet (pbuh) said:
“There is no fast for the person who did not intend to fast from the night before.”
The intention may be made at any point during the night, even if it is just a moment before Fajr. Niyyah means the resolution in the heart to do something; speaking it aloud is bid’ah (a reprehensible innovation), and anyone who knows that tomorrow is one of the days of Ramadan and wants to fast has made the intention.
If a person intends to break his fast during the day but does not do so, then according to the most correct opinion, his fast is not adversely affected by this; he is like a person who wants to speak during the prayer but does not speak. Some of the scholars think that he is not fasting as soon as he stops intending to fast, so to be on the safe side, he should make up that fast later on. Apostasy, however, invalidates the intention; there is no dispute on this matter.
The person who is fasting Ramadan does not need to repeat the intention every night during Ramadan; it is sufficient to have the intention at the beginning of the month. If the intention is interrupted by breaking the fast due to travel or sickness – for example – he has to renew the intention to fast when the reason for breaking the fast is no longer present.
If a person embarks on an obligatory fast, such as making up for a day missed in Ramadan, or fulfilling a vow, or fasting as an act of expiation (kafaarah), he must complete the fast, and he is not permitted to break it unless he has a valid excuse for doing so. In the case of a naafil fast, “the person who is observing a voluntary fast has the choice either to complete the fast or to break it” – even if there is no reason to break it.
If a prisoner or captive knows that Ramadan has begun by sighting the moon himself or by being told by a trustworthy person, he has to fast. If he does not know when the month is beginning, he must try to work it out for himself (ijtihaad) and act according what he thinks is most likely. If he later finds out that his fasting coincided with Ramadan, this is fine according to the majority of scholars, and if his fasting came after Ramadan, this is fine according to the majority of fuqahaa’, but if his fasting came before Ramadan, this is not acceptable, and he has to make up the fast. If part of his fasting coincided with Ramadan and part of it did not, what coincided with it or came after it is fine, but what came before is not OK. If the matter never becomes clear to him, then his fasting is fine because he did the best he could, and Allah burdens not a person beyond his scope.
