Crystal Reports for Rational Application Developer Designer Guide

The preset date ranges can be used to create selection formulas similar to these:

{file.DATE} in LastFullMonth

Selects those records in which the date found in the {file.DATE} field falls within the last full month. (If the month is May, this selects all records with an April date.)

not({file.DATE} in LastFullMonth)

Selects all records except those in which the date found in the {file.DATE} field falls within the last full month (if the month is May, this selects all records except those with an April date).