Strange Goings on with a date???

Question

Hi,
I have a loop that has a date and then for each time it goes around the loop it adds one week onto that date up to todays date and the displayed the date in a message box.
Just to test my code I made the date for today 10/04/05, the date in the loop is 17/03/05.
So, i want this loop to go round and print out the following dates:
17/03/05
24/03/05
31/03/05
07/04/05
as these are the dates between the first date and today (changed to 10/04/05, for testing).
It starts of ok as it shows:
17/03/05
24/03/05
But then something strange happens and the next two dates are:
08/04/05
29/04/05
I cant understand why it does this.
Here is some of the code:
for(int m = 0; m < missingAmount; m++){                                       
//add on the number of weeks each time to get all missing payment dates
dateOfOrder.add(Calendar.WEEK_OF_YEAR, + m);                                   
int day = dateOfOrder.get(Calendar.DAY_OF_MONTH);
int month = dateOfOrder.get(Calendar.MONTH);
int year = dateOfOrder.get(Calendar.YEAR);
String weekMissingPayment = "" + day + "/" + month + "/" + year;
JOptionPane.showMessageDialog(this, "This customer has to pay for orders for week " + weekMissingPayment);
}(by the way dateOfOrder is the date 17/03/05 with type Calendar)
Any ideas, if you are not sure about what I am trying to do then ask me questions to make it more understandable.
Cheers

Answer 1

You're adding one week, which changes that date. Then you add two weeks, to a date that's already one week later than the original, so now you're at +3 weeks.
Add 1 instead of m.