I have known alot of students, in many programs. On average I say students have classes 2 - 3 days a week, with 2 classes per day...
I know more than a few students attending top rated public universities.
According to one survey conducted by the National Survey of Student Engagement, most college students spend an average of 10–13 hours/week studying, or less than 2 hours/day and less than half of what is expected. Only about 11% of students spend more than 25 hours/week on schoolwork. [1]
a "Full time" course load is 15 credit hours, which is about 5 classes.. a student taking five 3-credit classes spends 15 hours each week in class..
In the past I have run college level internship programs, both for credit, and critically for this discussion not for credit (meaning no affiliation with the schools). I have had no problems scheduling students work around their course schedule, for which they normally have 2 or 3 open days for work.
[1] https://www.collegiateparent.com/academics/student-study-tim...