If someone were to ask: What is the evidence that one may break the fast on the basis of likelihood, even though the basic presumption is that daytime remains?
The answer is the hadith of Asma’ bint Abu Bakr, may Allah be pleased with them both, who said: “We broke our fast on an overcast day during the lifetime of the Prophet ﷺ.” (1) They undoubtedly broke their fast on the basis of likelihood, for she said in this hadith, “Then the sun appeared.” This shows that one may break the fast when he thinks it likely that the sun has set. If it then becomes clear that the sun had set, the matter is clear; and if nothing becomes clear, the matter is likewise clear. But if it becomes clear that it had not set, then, according to the established position of the school, he must make up the fast; while according to the stronger view, he does not have to make it up.
Issue: A man is on the ground when the sun sets, so he breaks his fast; then his plane takes off and he sees the sun again. What is the ruling?
We say: He is not required to resume abstaining, because the daytime period applicable to him has ended. The sun did not rise upon him; rather, he rose up to it. However, if the sun had not yet set, with five minutes remaining before it did, and then the plane took off, so that once it had risen the sun still had another quarter or third of an hour before setting, then his fast continues, because he is still required to fast.
His statement, “or believing it to be night, only for it to become clear that it was daytime,” means that if he eats believing that it is nighttime, but it becomes clear that it was daytime, his fast is invalid—whether this occurs at the beginning or the end of the day. If he eats believing it to be nighttime, whether on the basis of what he thinks likely or on the basis of the original presumption, and it becomes clear that it was daytime, then he must make up the fast. The jurists, may Allah have mercy on them, do not excuse ignorance in this matter; they say that what counts is the actual state of affairs.