Every clinical trials programmer is at some point going to encounter invalid numeric or date values collected in a character field.  There are many different methods of checking for valid numbers or dates in a character variable; from writing a validation macro to just using an input statement and hoping for the best.  Wouldn't it be useful if there were an easy to use SAS® function that would check if a character variable holds a valid numeric value, or a valid date?

With the introduction of the SAS Function Compiler (FCMP) procedure in SAS version 9.2 we can now define these SAS functions that we always wanted to have.  This paper will present some simple validation functions and some more complex date functions as examples of what can be achieved with PROC FCMP.