My calendar app has frozen whilst trying to sync to icloud.
When I open it it shows the 'syncing calendars" drop down with the working bar.
Nothing I do seems to get it to quit this so I am without calendar now.
Anyone have a suggestion as to how to solve this?
I tried to download Mavericks again but there seems to be no option for a selective instal as past versions of OSX.
Have you tried restarting the computer?
If yes, and no change, then I would proceed with reseting sync history or http://support.apple.com/kb/TS2481?viewlocale=en_US&locale=en_US (if Mountain Lion or older).
If using Mavericks, I would still be inclined to follow the basic steps in the second article to delete the contents of ~/Library/Caches and the Calendar Cache files in ~/Library/Calendars. Deleting caches is generally safe and often solves problems with applications hanging up.
Go to Finder
While pressing the "option" key, click Go->Library
Then navigate to the Calendars folder and the files starting with "Calendar Cache" to your desktop
Navigate to ~/Library/Caches and select all the files inside that folder. Drag them to your trash.
If these steps do not work, I would probably follow the steps above to go into the Library folder and then move the iCloud folder to your desktop, then restart.
Again, back up anything you can before hand.