I have a problem calculating number of days between two dates. I need to know if Date A is earlier or later than Date B. I tried the following:

Case(IsValid(Date of Death and Date of Death - Date of Charge), "Warning! Patient Desceased!", "")

This returns a valid result in all cases. Obviously, since most of the patients are still living, the Date of Death field is usually empty.

The record contains two dates. One is the Date of Death, and the other is the Date of Charge. If the Date of Death precedes the Date of Charge, there is a problem (can't make a charge for someone who is dead).

I think you mean:

Case ( Date of Death and Date of Death < Date of Charge, "Warning! Patient Deceased!" )

That works - guess I was trying to hard - thanks for the help.