Exchange 2010 update timezone of all calendar items

We are currently operating Exchange 2010 server with Outlook 2010 clients on a ship. We have just changed timezones for the first time in quite a while today. Is there any way to rebase all the calendars and/or update all the calendar items to the new timezone at the same time?

I have looked at the following tools already.

• Microsoft Exchange Calendar Update Configuration Tool - http://www.microsoft.com/en-us/download/details.aspx?id=6266 (Doesn't support exchange 2010)
• Time Zone Data Update Tool for Microsoft Office Outlook - http://www.microsoft.com/en-us/download/details.aspx?id=17291

The Time Zone Data Update Tool for Microsoft Office Outlook does work for individual users, but has some serious downsides. Including each user needs to run it (approx 400 users), and also it only seems to work on the default account in Outlook 2010, a lot of our users have role accounts as well that we would need to run the tool on. The only way I can find to get this tool to run on the role accounts is to make the role account the default account in outlook, and that in itself is quiet an involved process especially if you have 2 or 3 role accounts.

So is there a way to just change all calendar items on our Exchange server to a different timezone in one go? We are a little unique in terms of the whole organisation can change timezones over night, meeting rooms and all, but surely a product as advanced as Exchange 2010 allows us to do what we need.