Is the fast of one who sleeps most of his time during the daytime in Ramadan valid?

The fast of one who sleeps most of the day is valid by the consensus of scholars, because sleep does not invalidate the fast. However, for a fasting person to sleep most of the day is a dereliction on their part, and they should utilize Ramadan for acts of obedience. Sheikh Ibn Baz also advised fearing Allah and diligently observing obligatory duties, without being preoccupied from them by sleep or anything else.