Probably just trying to not get a late fee on their rent payment if if the due date fell on a weekendand they planned to leave it in the office drop box over the weekend... Of that was the case and they were paying with a check as long as it's in the office drop box by opening on monday morning then it's not late. But if it's a money order with the printed date on it, doesnt matter if it office was closed on due date because it has the date printed right on it.