I currently have:
Mac OS X 10.6.1
iCal Version 4.0 (1362)
iPhone Version 3.1.2
Zimbra Version 5.0.19
Time Zone +10GMT Brisbane/Australia enabled on everything
I have an appointment that appears correct in Zimbra Webmail and iCal however on my iPhone it is 1 hour behind. I have time zone support enabled in iCal and have the correct time zone in my Zimbra preferences and whether I enable time zone support or not on my iPhone it does not make a difference. I have temporarily had to change my Time Zone on my iPhone calendar to Sydney as they are currently in daylight savings in order to have the correct appointment times.
Example: Appointment scheduled for 13:00 today would be correct in iCal and Webmail Calendaring however it would show as 12:00 today on the iPhone.
This issue seems to be isolated to iPhone 3.1.2 fw only as users on 3.1 (or below) do not seem to have this problem.
Any help greatly appreciated!