She sent an email to all us student workers reading (with some edits to style for anonymity): “Because Monday is a holiday, your timesheet are due today. If you don't submit it, you won't get next month's check.” This is illegal in my state. Regardless if timesheets have been submitted, employers can't withhold paychecks. Obviously, because we are students, we are assumed to be ignorant of the law and thus getting taken advantage of.