roll doesn't work properly

[mike nu]

Hi there,
I ran into a problem with the roll method of GregorianCalendar class. Suppose the date is April 6, 00:00:00 2002, the following code will go throught the time changes:
GregorianCalendar cal = new GregorianCalender();
for (int i = 0; i < 24; i++) {
cal.roll(Calenader.HOUR_OF_DAY, 1);
}
April 6 01:00:00 2002
April 6 02:00:00 2002
.................
April 6 22:00:00 2002
April 6 23:00:00 2002
April 6 00:00:00 2002
But if the current date is April 7, 2002 (daylight saving time change will occur at 2:00 am this day), the above code will result:
April 7 01:00:00 2002
April 7 02:00:00 2002
.................
April 7 22:00:00 2002
April 7 23:00:00 2002
April 6 23:00:00 2002
April 6 00:00:00 2002
Can anyone tell me how to fix this problem or how to avoid this problem.
Thanks a lot.

[Cindy Glass]

There is a bug report open for this at: http://developer.java.sun.com/developer/bugParade/bugs/4312621.html
Their suggestion:
Use the add() method, instead of roll().