DateValue exception output misleading #22

What steps will reproduce the problem?
1. Create a new DateValue with any month with 31 days who's following month has 
30 days, setting the day to 31.
2. You get an exception saying wrong date format.
3.

What is the expected output? What do you see instead?
The expected exception would be, for month=3:
Month=3 is April in GregorianCalendar, April has 30 days. March has 31 days.

The exception says: wrong date format YYYY-DD-MM 2010-31-3.
The exception *should* say: wrong date format YYYY-DD-MM 2010-31-4.

It is misleading because the date in March is correct, and the month printed is 
not _month+1_, like in other methods of this DateValuue class.

This exception should also increment the month in it's reporting. 

What version of the product are you using? On what operating system?
data source lib v1.0.2 
2.6.32-22-generic #36-Ubuntu x86_64 GNU/Linux

Please provide any additional information below.