As DS says, there is no time for activities that waste time. His days and nights are full with classes, sports, clubs. Fortunately, he considers his sport to be 'fun time'. With 20 units, he has only one day during the school week that has a 2 hour break, but other than that he's in class until his team practices in the afternoon.
He has become a fan of the index card and seams to always have a stack of 'flash cards' with him wherever he goes. He has a little bit of downtime on Sunday.
He's a Youngster now, and actually feels like he has more time on his hands than when he was a Plebe! Plebe year he used his weekends to get caught up. That year, he learned to be organized, always prepared, tried to not be caught off guard. The mids in his company that didn't do as well, put things off for another day. If you start out that way, you'll never catch up.