Issues with cal.add?

I have the following method in my class:

        private int newDate(int date, int increment, int targetYear) {
                int retdate = 0;
                if (date > 0) {
                        int year = date / 10000;
                        int month = (date - (year * 10000)) / 100;
                        int day = date - ((year * 10000) + (month * 100));
                        year = targetYear;
                        Calendar cal = new GregorianCalendar(year, month, 
day);
                        cal.add(Calendar.DATE, increment);
                        year = cal.get(Calendar.YEAR);
                        month = cal.get(Calendar.MONTH);
                        day = cal.get(Calendar.DAY_OF_MONTH);
                        retdate = (year * 10000) + (month * 100) + day;
                }
                return retdate;
        }

It should take the date and decrease by the amount of the increment using 
the targetYear as the year of the date instead.  Here's the problem.  I 
sent it the following parms:
date = 20050502; increment = -2, targetYear = 2007.  When it gets to the 
cal.add(Calendar.DATE, increment) the value of the date is 2007/05/02 and 
I want to decrease it by 2.  It returns 2007/04/31  wtf?  There is no such 
date.  Is this an issue with the calendar class?  Thanks,

Ron Power
Programmer
Information Services
City Of St. John's, NL
P.O. Box 908
St. John's, NL
A1C 5M2
709-576-8132
rpower@xxxxxxxxxx
http://www.stjohns.ca/
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