And in order to ensure that he has been fasting throughout this time he should begin abstaining earlier than the Adhan for Fajr prayers, and continue to refrain for some time after sunset from acts which invalidate a fast.
2. A person can make niyyat every night of the holy month of Ramadhan that he would be fasting on the following day, and it is better to make niyyat on the first night of Ramadhan that he would fast throughout that month.
3. The last time for making niyyat to observe a fast of Ramadhan for a conscious person, is moments before Adhan of Fajr prayers. This means he must be intent upon fasting at that time, even if he later became heedless of his intention due to sleep etc.
4. As for Mustahab fast one can make its niyyat at any time in the day, even moments before Maghrib - provided he has not committed any such act which invalidates the fast.
5. If a person sleeps before Adhan for Fajr prayers in Ramadhan or any other day fixed for an obligatory fast without making a niyyat, and wakes up before Zuhr to make a niyyat of fast, his fast will be in order. But if he wakes up after Zuhr, as a precaution, he should continue with the abstinence with the niyyat of Qurbat and then give its qadha also.
6. If a person intends to keep a fast other than the fast of Ramadhan, he should specify that fast; for example, he should specify it as the qadha fast or a fast to fulfil a vow. On the other hand, it is not necessary that a person should specify in his niyyat that he is going to observe a fast of Ramadhan. If a person is not aware or forgets that it is the month of Ramadhan and makes a niyyat to observe some other fast it will be considered to be the fast of Ramadhan.
7. If a person knows that it is the month of Ramadhan, yet intentionally makes an intention of observing a fast other than the fast of the month of Ramadhan his fast will not be reckoned a fast of the month of Ramadhan nor the fast of which he made the niyyat.
8. If a person observes fast with the niyyat of the first day of the month and understands later that it was the second or third of the month, his fast is in order.
9. If a person makes an intention before Adhan for dawn prayers to observe a fast and then becomes unconscious and regains his senses during the day time, he should, on the basis of obligatory precaution, complete the fast on that day, and if he does not complete it, he should observe its qadha.
10. If a person makes niyyat before the Adhan for Fajr prayers to observe a fast and then gets intoxicated and comes to senses during the day he should, on the basis of obligatory precaution, complete the fast of that day and should also give its qadha.
11. If a person makes a niyyat before the Adhan for Fajr prayers to observe a fast, and then goes to sleep, and wakes up after Maghrib his fast is in order.
12. If a person did not know or forgot that it was the month of Ramadhan, and takes notice of this before Zuhr and if he has performed some act which will invalidates a fast, his fast is void. But, he should not perform any act till Maghrib which invalidates a fast and should also observe qadha of that fast after Ramadhan. The same rule applies if he learns after Zuhr that it is the month of Ramadhan. But if he learns before Zuhr, and if he has not done anything which would invalidate his fast, his fast will be valid.
13. If a child reaches the age of puberty before the Adhan for Fajr prayers in the month of Ramadhan he/she should keep fast and if he/she reaches the age of puberty after the Fajr Adhan, the fast of that day is not obligatory for him/her except if he/she intended to observe a Mustahab fast on that day, then he/she can complete it as a Mustahab precaution.
14. If a person who has been hired to observe the fasts of a dead person or has fasts of Kaffarah upon him as an obligation, observes Mustahab fasts, there is no harm in it. However, if a person has his own qadha of fasts, he cannot observe Mustahab fasts.
If he forgets this and observes a Mustahab fast and remembers it before Zuhr his Mustahab fast will be void and he can convert his intention to the fast of qadha, and if he takes notice of the situation after Zuhr his fast is void as a precaution, and if he remembers this after Maghrib, his fast is valid.
15. If it is obligatory for a person to observe a specific fast other than the fast of the month of Ramadhan, for example , if he has vowed that he would observe fast on a particular day, and he does not make an intention purposely till the Adhan for Fajr prayers, his fast is void.
And if he does not know that it is obligatory for him to fast on that day or forgets about it and remembers it before midday, and if he has not performed any act which invalidates the fast and makes an intention to fast, his fast is in order, and if he remembers after Zuhr, he should follow the precaution applied to the fast of Ramadhan.
16. If a person does not make an intention till near Zuhr for an obligatory fast which has no fixed time, like a fast of Kaffarah, there is no harm in it. In fact, if he had decided before making a niyyat that he would not fast, or was undecided as to whether he should or should not fast, if he has not performed any act which invalidates a fast, and decides before Zuhr to fast, his fast will be in order.
17. If a non-Muslim embraces Islam in the month of Ramadhan before Zuhr, he should, on the basis of obligatory precaution, make an intention to fast, and complete it provided that he had not committed any act which would make a fast void. And if he does not observe fast on that day he should give its qadha.
18. If a patient recovers from his illness in the middle of a day in the month of Ramadhan, before Zuhr, and if he has not done anything to invalidate the fast, he should make niyyat and fast. But if he recovers after Zuhr, it will not be obligatory on him to fast on that day.
19. If one doubts whether it is the last day of Sha'ban or the first day of Ramadhan then the fast on that day is not obligatory. If however, somebody wants to observe fast on that day he cannot do so with the intention of observing the Ramadhan fast, but if he makes an intention that if it is Ramadhan then it is the Ramadhan fast and if it is not Ramadhan then it is qadha fast or some other fast like that, his fast will most probably be excepted, But it is better to observe the fast with the intention of qadha fast or some other fast, and if it is known later that it was Ramadhan then it will automatically be Ramadhan fast. And even if he makes a niyyat of a natural fast, and later it becomes known that it is Ramadhan, it will be sufficient (i.e. that fast will be counted as the Ramadhan fast).
20. If it is doubtful whether it is the last day of Sha'ban or the first of Ramadhan, and a person observes a qadha or a Mustahab fast or some other fast on that day, and later comes to know the same day that it is the first of Ramadhan, then he should convert the intention to the Ramadhan fast.
21. If somebody is undecided in his niyyat whether to break or not an obligatory fixed fast, like that of Ramadhan, or decides to do so, in this situation if he doesn’t repeats his Niyyat then his fast will be void, but if he repeats his niyyat then on the basis of obligatory precaution he should complete his fast and should give its Qadha.
22. If, while observing a Mustahab fast or an obligatory fast the time of which is not fixed (e.g. a fast for Kaffarah) a person intends to break the fast or wavers whether or not he should do so, and if he does not break it, he should make a fresh niyyat before Zuhr in the case of an obligatory fast, and before Maghrib in the case of a Mustahab fast. That way his fast will be in order.