or thirty days. This is because Allah, exalted is He, says:
“The month of Ramadan is that in which the Quran was sent down.” [al-Baqarah 2:185]
Allah calls it a month even though it may consist of twenty-nine days or thirty days.
But if he begins in the middle of a month—for example, if he starts fasting on the fifteenth—one view is that he must fast thirty days, since it is not possible to base the calculation on the lunar month. Another view is that he is required only to fast the actual length of that month and is not required to fast thirty days. According to this view, if he begins fasting on the fifteenth day of this month, he finishes on the fourteenth day of the following month. Thus, if the month in which he began fasting is assumed to be incomplete, he fasts twenty-nine days. This is the correct view: he is required only to fast one lunar month, whether he begins during the month or at its beginning.
If we hold that consecutive fasting is required—meaning in the case where he is obligated to fast consecutively—and he breaks that continuity by not fasting one day of the month, must he begin anew or complete what remains?
The answer is that there are details to consider. If this occurs due to a valid excuse, he does not begin anew; rather, he continues from where he left off. For example, a man begins fasting and fasts ten days, then falls ill with an illness that permits him to break the fast, so he does not fast for five days. He then completes his fast on the basis of the first ten days, because he broke the fast for a valid excuse.
Similarly, if he travels after fasting ten days and breaks his fast while travelling, then returns from his journey, he continues from where he left off, because travel is an excuse that permits breaking the fast even in a fast made obligatory by the Sacred Law itself, namely Ramadan. However, if he travels in order to break his fast, we say: It is forbidden for you to break your fast, because consecutive fasting is binding upon you, and breaking the fast is incompatible with consecutiveness. If he does break his fast, he must begin anew, because he broke it for an excuse that does not permit breaking the fast.