Time of Fasting

Q: At night, I decided to fast the following day; however, I didn’t wake up during saḥar in order to make the intention; instead, I woke up just before sunrise. Will my fast be deemed valid?

A: The fast is valid.

Q: Is it permissible to break one’s fast at the start of the maghrib adhān?

A: This is unproblematic assuming one is certain the maghrib time has arrived; assuming one doubts or conjectures the arrival of maghrib, breaking one’s fast is not allowed.