Error in Calendar.add (almost) evey last Monday of March

Question

Is the following a known bug? I am running under Windows 2000 and using
C:\jdk1.4>java -version
java version "1.4.1"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1-b21)
Java HotSpot(TM) Client VM (build 1.4.1-b21, mixed mode)
* Filename: CalendarBug.java
* Every last Monday of March (except those with a whole week after it),
* gives a wrong result when subtracting 24 hours with the Calendar.add function.
* These specific dates give -25 hours...
* Selected output:
* Set date: Mon Mar 26 00:00:00 CEST 2001
* -->Adjusted 24 hours: Sat Mar 24 23:00:00 CET 2001
* Set date: Mon Mar 25 00:00:00 CET 2002
* Adjusted 24 hours: Sun Mar 24 00:00:00 CET 2002
* Set date: Mon Mar 31 00:00:00 CEST 2003
* -->Adjusted 24 hours: Sat Mar 29 23:00:00 CET 2003
* Set date: Mon Mar 29 00:00:00 CEST 2004
* -->Adjusted 24 hours: Sat Mar 27 23:00:00 CET 2004
* Does anyone care to explain?
* The result is the same when substituting seedDate.add(Calendar.HOUR,-24) with
* - seedDate.add(Calendar.HOUR_OF_DAY,-24)
* - seedDate.add(Calendar.MINUTE, -24*60)
* Date Created: 25. september 2003 09:53:20
* Written by: Skjalg Bjorndal
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
public class CalendarBug {
    GregorianCalendar seedDate = new GregorianCalendar();
    public void lastMondayInMarch(int year, int month, int date) {
        System.out.println("   ------- Year: " + year + " ----------");
        for (int i = 0; i < 10; i++) {
            System.out.println("   ---------- " + i + " ----------");
            seedDate.set(year, month, date + i);
            seedDate.setTime(zeroTime(seedDate.getTime()));
            System.out.println("   Set date:          " + seedDate.getTime().toString());
            seedDate.add(Calendar.HOUR, -24);
            if (seedDate.get(Calendar.HOUR_OF_DAY) != 0) {
                System.out.print("-->");
            } else {
                System.out.print("   ");
            System.out.println("Adjusted 24 hours: " + seedDate.getTime().toString());
        System.out.println("");
    private Date zeroTime(Date date) {
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        // Zero out time:
        cal.set(Calendar.HOUR_OF_DAY, 0);
        cal.set(Calendar.MINUTE, 0);
        cal.set(Calendar.SECOND, 0);
        cal.set(Calendar.MILLISECOND, 0);
        return cal.getTime();
    public static void main(String args[]) {
        CalendarBug aBug = new CalendarBug();
        aBug.lastMondayInMarch(2001, 2, 19);
        aBug.lastMondayInMarch(2002, 2, 18);     // OK - hole week after last Monday of month
        aBug.lastMondayInMarch(2003, 2, 24);
        aBug.lastMondayInMarch(2004, 2, 22);

Answer 1

Thanks for both of your prompt replies!
The number of hours to be subtracted is configurable in a property file in the program in which the problem arose. I.e. it could be 1, 23, 24, 120 or whatever...
My solution will be to download 1.4.2, as kurisu1 pointed out would solve the problem.
Until we tested the rest of the code with 1.4.2, I will reprogram and use the seedDate.add(Calendar.DATE, -1); as a temporary work around.
Best regards
__Skjalg