At least 3 to 4 a year. When I ask them, their job is scheduling them to start at 2 or 230 (or earlier) when school ends at 245. The disappointment in their eyes when I say no just saddens me that their employer has conditioned them to feel ashamed that, as a student, no, they cannot make their 2pm shift.
I'm all for kids having a part time job for extra cash, but the disregard of these employers for the education of literal children disgusts me.