Just as an example, my son is now at a D2 university (transferred from a JuCo) and he has practice or conditioning every day. His only day off from baseball is Wednesday. Otherwise he has classes between 8 am and 2 pm followed by practice or conditioning. Some days they have conditioning early before class.
When he was at the junior college, his day off was Monday, with classes nearly everyday til about 2 pm, then practice from 3-6 pm. During the season it gets tougher with doubleheaders on Saturday and Sunday with a game or two during the week.