I have a "no make up rule" or "late" rule the day of the exam. I clearly explain this at the begining of the class. The students clearly understand. I have the highest attendance rate on those days. The only exception is that if they tell me ahead of time, they may take it the day before, after school, or if it is an issue like they go home sick, but I have seen them that day. They may take it the nexy day. If their child is sick and they call and leave a message, I let them come sfter school or have another person in the school administer it, same day only. It works well, and there is no misunderstanding. Last week I had two ladies take the test the day before. My students truely respect the rule.