Is the fast of one who wakes up three hours after the time of iftar valid, or must he make it up?

It is desirable for the fasting person to hasten breaking the fast, due to the Prophet's (peace and blessings be upon him) saying: "My Ummah will remain upon goodness as long as they hasten breaking the fast and delay the pre-dawn meal (suhoor)." Deliberately delaying breaking the fast is disliked and causes one to miss out on great reward. There is no blame upon someone who is asleep, or has forgotten, or a traveler who could not find anything with which to break their fast.