Seems like the daylight savings issues are continually biting. On the bright side the fix this year for MOSS is a very simple xml change. Simply navigate to “C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\12\CONFIG” and edit “timezone.xml”. I’d recommend making another copy of timezone.xml at this point just in case. The example here fits for East Coast Australia 2008. Simply go through file until you find your particular timezone, then modify the values or Month Day Hour, just remember that Day is actually the week that it changes ie in this example DST starts in the first week of October this year in Melbourne. It’s all pretty straight forward.
<TimeZone ID="76" Name="(GMT+10:00) Canberra, Melbourne, Sydney" Hidden="FALSE"><Bias>-600</Bias><StandardTime><Bias>0</Bias><Date><Month>4</Month><Day>1</Day><Hour>3</Hour></Date></StandardTime><DaylightTime><Bias>-60</Bias><Date><Month>10</Month><Day>1</Day><Hour>2</Hour></Date></DaylightTime></TimeZone>