Add date on Calendar

I try to create the code below. today is 7/2/07, but when I -2 days it shows 6/31/07. but there is no such a date. what do I do to make it go to 6/30/07?

Calendar now = Calendar.getInstance();

Calendar calendar;

calendar = (Calendar) now.clone();

//date of calendar is 6/2/07

calendar.add(Calendar.MONTH, 1);

//date of calendar is 7/2/07

calendar.add(Calendar.DAY_OF_YEAR, -2);

//date of calendar is 6/31/07

[462 byte] By [aboostera] at [2007-11-27 9:22:35]