Update: The fixes for this issue have been released in 11.5 (Entourage 2004) & 12.1 (Entourage 2008) Updates for Office for Mac.

I wanted to quickly provide this workaround to the users of Entourage 2004 & 2008 in Australia & New Zealand (ANZ) time zones until Microsoft releases fixes thru updates at Mactopia website.

Issue
When Entourage 2004 & 2008 users organize meetings by inviting other users who are using Microsoft Outlook or OWA (Outlook Web Access) against their Exchange mailboxes (version of Exchange Server does not matter here), then those meeting attendees may see the incoming meeting invite being an hour off. This issue is not seen if all meeting attendees are Entourage users.

Cause
This happens as Entourage 2004 & 2008 use DST information from related 'Timezones' files for users in ANZ time zones, which are not up to date with current information.

Resolution
Microsoft is working to release a fix for this issue in an update for both versions of Entourage but a final release date is not available yet. When that update is available, users can safely install it and it will replace the files which they will put on their systems as a result of applying the workaround provided below.

Workaround
Below are the steps to follow for both versions of Entourage. Only Entourage users will need to apply this workaround on their machines, no action is required by other users who are using Microsoft Outlook or OWA.

Entourage 2004

1. Quit Entourage (Entourage should not be running when you apply this workaround)
2. Back up the current 'Timezones' file in folder: Mac Hard Drive : Applications : Microsoft Office 2004 : Office (just copy it to a backup folder on your hard drive)
3. Download the updated 'Timezones' file for Entourage 2004 from here (extract its content before proceeding to next step)
4. Copy the downloaded 'Timezones' file to the same location as above in Step 2, replacing the existing 'Timezones' file
5. That's it, you are done, launch Entourage and every meeting you create now will not display the issue described above

Entourage 2008

1. Quit Entourage (Entourage should not be running when you apply this workaround)
2. Back up the current 'Timezones.ics' file, go to folder: Mac Hard Drive : Applications : Microsoft Office 2008 : Office, locate a file by the name of 'EntourageCore.framework', now Control-Click on it and choose 'Show Package Contents' in the resulting menu, a new window will appear, in that window go to folder: Versions : 12 : Resources : en.lproj (you will find the 'Timezones.ics' file here, just copy it to a backup folder on your hard drive)
3. Download the updated 'Timezones.ics' file for Entourage 2008 from here (extract its content before proceeding to next step)
4. Copy the downloaded 'Timezones.ics' file to the same location as above in Step 2, replacing the existing 'Timezones.ics' file
5. That's it, you are done, launch Entourage and every meeting you create now will not display the issue described above

Note: Any meetings which were scheduled earlier and display the issue described in this post will not automatically get fixed. If you want to fix them, you will have to open them and make a change in them (like add one character to its subject/title or notes area, etc.), then save them and send update to all attendees. This change will force Entourage to recalculate DST info as per the updated 'Timezones' file.

Workaround Removal
If at anytime you may need to remove or undo this workaround, just follow the same steps as above and replace the 'Timezones' files with the original ones which you backed up earlier.