Using syncevolution you are very flexible in your calendar selection and it supports CalDav. It requires some work on the command line.
A good description how to set up your device you can find here: http://tanghus.net/2012/07/syncing-y...oud-an-update/
This is talking about a n900, but the setup is basically the same.
Syncevolution for your N9 you can find here: https://openrepos.net/content/holgern/syncevolution

There is even a simple GUI if you want to use it on the long run: https://openrepos.net/content/holgern/syncevolution-gui