What do I do When my Outlook Calendar is Freezing…

What do I do When my Outlook Calendar is Freezing… Well:
1) I rename my ost file to ost.old located in (in my case):

C:\Users\\AppData\Local\Microsoft\outlook\outlook.ost

2) Re-launch outlook.

By doing so you actually force a re-sync with the Exchange (outlook) server and get a fresh .ost file.
WARNING: If your outlook is not syncing with a server (which is often the case, especially for local install) this will not work.