FULL PRODUCT VERSION :
java version "1.6.0_01"
Java(TM) SE Runtime Environment (build 1.6.0_01-b06)
Java HotSpot(TM) Client VM (build 1.6.0_01-b06, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Windows XP

A DESCRIPTION OF THE PROBLEM :
For the Australia/Perth timezone the useDaylightTime() returns False even though Western Australia(Perth) is currently using DST and has an offset change from +8 to +9.
 Although Western Australia's use of DST is just a trial until 2009 according to the TimeZone javadocs the useDaylightTime() method "Queries if this time zone uses daylight savings time." Therefore even during their trial of DST this method should return TRUE.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Compute offset using Australia/Perth timezone on October 27, 2007 (offset should be +8)
Compute offset using Australia/Perth timezone on October 28, 2007 (offset should be +9)
Call to useDaylightTime() will return FALSE, however based on the different offset mentioned above, this method should return TRUE.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
useDaylightTime() should return TRUE for Australia/Perth timezone.
ACTUAL -
useDaylightTime() returns FALSE

REPRODUCIBILITY :
This bug can be reproduced always.