First published on TECHNET on Mar 07, 2007

Q: I patched my exchange 2003 sp2 servers 2 weeks ago with OS and Exch. hotfixes, but didn’t run the exchange / outlook tool, what is my best option? Should I run the tool right away or just have the users rebook everything? I'm afraid the tool will move back ALL appointments.
A: First of all, your risk is on the single-instance appointments created after you patched the clients that fall within the four week extended DST period.  The reason for this is that while recurring meetings retain DST info, pre-Outlook 2007 single-instant appointments do not.  Therefore, the rebasing tool will assume that even the post-patching appointments are DST2006 (when they are really DST2007, i.e., correct) and move them anyway.

I would suggest that you configure the CommandLine parameter with the following value: tzmove.exe /q /onlyrecurring .(Ref: ).  Then have the users move single-instance appointments -- since they will know if they need to be moved.