Right now, my N900 is in a coma, I'm stuck with my substitute Nokia C7 until my Jolla arrives.
Now my C7 syncs its calendar with Google via Exchange Active Sync. That works only via a paid third-party service, Nuevasync.
And that is the only way I can sync my C7 with anything non-Microsoft powered.
Why? Because the last Symbian supports but two syncing protocols: a proprietary one (MfE) and an open, but outdated one (SyncML) that nobody supports anymore (e.g. Google dropped it January this year).
Why am I talking about this here? Because as far as i can tell (please correct me if you know better), right now Sailfish has that very same situation as in abandoned old Symbian - except I don't even know if SyncML is there.
We have to rely now on some android app working to fill the gap....