Tzmove and /forcerebasesuppressallupdates
We have had a few questions about Tzmove and using the /forcerebasesuppressallupdates switch.
We do not recommend that customers use the /forcerebasesuppressallupdates switch with tzmove because ALL appointments in a users Calendar are updated regardless of who the organizer of the meeting is. In addition, no updates to meetings are sent out to any attendees. The difficulty that is introduced due to these two factors is that every Calendar that has meetings in the organization has to have the /forcerebasesuppressallupdates command-line switch ran on their Calendar within a very short period of time. It’s difficult to coordinate this and it goes against how Outlook is designed to update meetings through meeting updates.
One example of the type of problem you could encounter would be if one user sent out a meeting series to 10 people and 5 of them already had the /forcerebasesuppressallupdates switch ran. When the remaining 5 have /forcerebasesuppressallupdates ran then those appointments will be at a different time than the other attendees and possibly even different than the organizer. In addition, meeting attendees that are outside of the Exchange organization would not get meeting updates so they would likely have to manually move those appointments or the appointments would be incorrect. There are other scenarios but you probably get the point.
As far as running the tool from the command-line. The syntax you are looking for is as follows with “User” being the mailbox owner:
tzmove /Q /FORCEREBASESUPPRESSALLUPDATES \\Mailbox - User\Calendar
Since you are using the /Q switch then you should look at the TZMOVE events in the Application Event log for information regarding how the tool executed.
Generally speaking we don't recommend that /FORCEREBASESUPPRESSALLUPDATES be used with user calendars, noting the risks in the "Issues" sections of https://support.microsoft.com/kb/933146.
See also https://blogs.technet.com/dst2007/pages/quick-reference.aspx