For anyone struggling w/ a way to filter a repeating section by month in IP 2003, I wanted to share this
Assuming your date record is called StartDate
Create a data field called "ShowPeriod" as a whole number (integer)
Create a drop down w/ values 1-12 and corresponding labels Jan - Dec
On repeating section, add the following expression to a filter
contains(substring(@StartDate, 6, 2), ../../my:Showperiod)
Thanks,