It looks like you can set Hiri as the default mail app but not the default calendar app. Using Ubuntu any version.
To do so I think Hiri requires CalDAV and CardDAV support.
+1 I also want this feature. Ubuntu 18.04 uses Gnome-shell, and has a nice calendar in the notification center. It would be great to be able to see Hiri calendar events in this area.
+1. This would rock.
I would like to know if there is a way to do this as well
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