You can export your contacts to vcf, probably best to merge them into one file afterwards and import that to your Jolla. All other ways I tried like direct sync with n9 did not work (people claim it works and it does partially, contacts with special chars or something odd do not get synced).

For calendar, I actually did not do any of this but syncevolution should work on n900 and people said it did (just recently I read about problems) work on their Jolla.

If you want to try I can give you access to my owncloud server (ssl, userdata encrypted, if you do not trust me with some calendar entries you may delete them after the sync and tell me to delete your account), contact me on IRC