What is the ruling on someone who intended to fast, then forgot and ate and drank, so is their fast valid if they remember before Maghrib, and is it sufficient if they remember after Maghrib?

Whoever forgets and eats or drinks while fasting, let him complete his fast. His fast is valid, whether it is an obligatory or a supererogatory fast. This is the preponderant opinion among the scholars, based on the saying of the Prophet, peace and blessings be upon him: "If he forgets and eats or drinks, then let him complete his fast, for it was Allah who fed him and gave him drink."