The ruling on one who eats while in doubt about the dawn or the setting of the sun

Question:
May Allah reward you, Honorable Shaykh. This questioner says: If a Muslim is certain that the dawn has not yet appeared and he eats, but then it becomes clear to him that the dawn has appeared, what is the ruling? The same applies to the setting of the sun.

Answer:
This has passed through you. In the lesson on Islamic jurisprudence, it was stated that if one eats while in doubt about the appearance of the dawn, his fast is valid as long as it does not become clear to him that he ate after the dawn had appeared, because the default is the continuation of the night. As for one who eats while in doubt about the setting of the sun, his fast is invalid if he did not fast due to the continuation of the day. It is not permissible for him to fast until he is convinced in his opinion that the sun has set, and doubt is not sufficient. So there is a difference between the two issues: between one who eats while in doubt about the appearance of the dawn and nothing becomes clear to him, in which case his fast is valid, because the default is the continuation of the night, and between one who eats while in doubt about the setting of the sun, in which case it is not permissible for him until he is convinced in his opinion that the sun has set, or he is certain of it in his heart, because the default