> But then you're not dealing with dates at all, just categories which happen to have names that look like dates, no? If you and your client disagree about wha

> But then you're not dealing with dates at all, just categories which happen to have names that look like dates, no? If you and your client disagree about what constitutes a date, that doesn't mean "your client is wrong" it means "you need better communication. You can't fix this problem by requiring everyone use consistent definitions. Instead the solution is to check assumptions as often as possible.