1. That he is certain dawn has not yet broken—for example, if dawn is at five o’clock and he eats and drinks at four thirty—then his fast is valid.

2. That he is certain dawn has broken, such as if, in the previous example, he eats at five thirty. In that case, his fast is invalid.

3. That he eats while uncertain whether dawn has broken or not, though he considers it more likely that it has not broken. His fast is valid.

4. That he eats and drinks while considering it more likely that dawn has broken. His fast is likewise valid.

5. That he eats and drinks while undecided, with neither possibility outweighing the other. His fast is valid.

All of this is derived from the saying of Allah, the Most High:

“Eat and drink until the white thread of dawn becomes distinct to you from the black thread [of night].” [al-Baqarah 2:187]

Is this conditional upon its not later becoming clear that he ate after dawn had broken?

The stronger view is that it is not conditional upon this. Even if it later becomes clear to him that dawn had broken, his fast is valid, on the basis that he is excused for his ignorance at the time.

According to the established position of the school, however, if it becomes clear that he ate after dawn had broken, he must make up the fast, on the basis that ignorance is not an excuse. The correct view is that he does not have to make it up, even if it becomes clear that he ate after dawn, because he was unaware. Moreover, Allah permitted him to eat until it became clear to him. One of the established principles of Islamic jurisprudence is that whatever results from something permitted entails no liability; that is, it carries no legal consequence, because it was permitted.