J2sdk 1.4 Timezone bug?

Question

Set timezone to be GMT and run this piece of code in j2sdk1.4,
     System.out.println(
       "ZONE_OFFSET 1: " + ((new GregorianCalendar()).get(Calendar.ZONE_OFFSET))
     System.out.println(
       "ZONE_OFFSET 2: " +
       ((new GregorianCalendar(1970, 0, 1)).get(Calendar.ZONE_OFFSET))
     System.out.println(
       "ZONE_OFFSET 3: " +
       ((new GregorianCalendar(1971, 9, 30)).get(Calendar.ZONE_OFFSET))
     System.out.println(
       "ZONE_OFFSET 4: " +
       ((new GregorianCalendar(1971, 10, 1)).get(Calendar.ZONE_OFFSET))
     System.out.println(
       "ZONE_OFFSET 5: " +
       ((new GregorianCalendar(1972, 0, 1)).get(Calendar.ZONE_OFFSET))
     );It will print:
ZONE_OFFSET 1: 0
ZONE_OFFSET 2: 3600000
ZONE_OFFSET 3: 3600000
ZONE_OFFSET 4: 0
ZONE_OFFSET 5: 0while in jdk1.3, it prints correct answers:
ZONE_OFFSET 1: 0
ZONE_OFFSET 2: 0
ZONE_OFFSET 3: 0
ZONE_OFFSET 4: 0
ZONE_OFFSET 5: 0Another strange thing is that in other timezone such as US EST, j2sdk1.4 will print the correct numbers after running the above code:
ZONE_OFFSET 1: -18000000
ZONE_OFFSET 2: -18000000
ZONE_OFFSET 3: -18000000
ZONE_OFFSET 4: -18000000
ZONE_OFFSET 5: -18000000It seems to be a bug in j2sdk1.4.
Help is appreciated.

Answer 1

There is no "default offset" for a Calendar. The
zone offset depends on the default time zone. The default zone in turn depends
on the host zone. There is no reason to expect the value of
Calendar.get(ZONE_OFFSET) to necessarily remain constant between releases or
even between machines in the same release or between runs on the same machine.