Al-Imaam Muhammad ibn Saalih al-’Uthaymeen (may Allaah have mercy upon him) stated:

“In this matter there are five categories:

1. The person is sure that Fajr hasn’t appeared. As an example: The appearance of Fajr is at five o’clock and the person ate and drank at four thirty. His fast is sound.

2. The person is sure that Fajr has appeared. As an example the person ate at five thirty (although Fajr appeared at five). This person’s fast is invalid.

3. The person eats but he’s not sure whether or not Fajr has appeared. However it overwhelms his belief that Fajr hasn’t appeared. His fast is sound.

4. He eats and drinks and it overwhelms his belief that Fajr has appeared. His fast is not sound.

5. He eats and drinks wavering back and forth (as to whether Fajr has appeared or not) and there’s nothing overwhelming with him in this matter. His fast is sound.”

The Shaykh went on to say: “Even if it becomes clear to him that Fajr had appeared already, his fast is sound based upon (the principle in Islaam of) being excused due to ignorance in this situation.”



[Taken from: "ad-Durur al-Manthoor fee Ahkaam al-Iftaar was-Suhoor"