The ruling on the fast of one who ate or drank while in doubt about the dawn

Question: What is the ruling on the fast of one who ate or drank while in doubt about the dawn or the setting of the sun? Please inform us, may Allah reward you.

Answer: If one ate or drank while in doubt about the dawn, he owes nothing, and his fast is valid; provided it is not established that he ate or drank after the dawn had appeared; because the original state is the continuation of the night, and it is prescribed for the believer to take the pre-dawn meal before the time of doubt, as a precaution for his religion and out of concern for the perfection of his fast.
As for one who ate and drank while in doubt about the setting of the sun, he has erred and he must make up the fast; because the original state is the continuation of the day, and it is not permissible for a Muslim to break his fast except after being certain that the sun has set or having a strong presumption that it has set, and success is from Allah.