Calculating the Difference Between Two Dates Using PHP

Suppose you want to know the age of a person given her birth date. Let's say her birth date is "09-23-1969". Although in this case you might say that we don't need a program to compute the age, but assume there are 1000s of records in your database and for every person you have to print a report like:

What Are We Teaching PR Students?

How to do brochures, throw parties, talk to reporters and write press releases? Or, are we teaching them what PR's fundamental premise says we should be teaching them?