Java date annual calculation is closed two days a year

If you can imagine, this will cause Y2K style errors in my software Strangely, the annual calculation only takes place on two days of the year. I'm not sure how to troubleshoot

Output:

03-Jan-2013
02-Jan-2013
01-Jan-2013
31-Dec-2013 ** strange
30-Dec-2013 ** strange
29-Dec-2012
28-Dec-2012
27-Dec-2012
26-Dec-2012
25-Dec-2012

I don't know which part of the Java date utility might cause such an error

Code (since the test is very small, I include a complete working program):

import java.util.Calendar;
import java.util.Date;
import java.text.SimpleDateFormat;

public class DateT {

        private static String getFormattedBackscanStartTime(int days) {

                SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MMM-YYYY");
                Calendar workingDate = Calendar.getInstance();
                workingDate.add(Calendar.DATE,-1 * days);

                String formattedStartTime = dateFormat.format(workingDate.getTime());
                return formattedStartTime;
        }

        public static void main(String args[]) {

                for(int i = 35; i < 45; i++) {
                        System.out.println(getFormattedBackscanStartTime(i));
                }
        }
}

Solution

This is the problem:

"dd-MMM-YYYY"

Yyyy is an anniversary, not a calendar year You want yyyy instead

The last two days of 2012 are in the first week of 2013 You can usually only use the annual and weekly specifiers (W)