FYI: aCalendar+ does this, using OpenTasks storage backend. (Not open source though.)
Feature Request: Export/backup configuration option
I can’t get into DAVx5 right now (see my most recent post), but if DAVx5 doesn’t have an export/backup configuration option, it would be most welcome. Merci!
@croissant It’s on our (very long) roadmap already… However this is a very complicated task and many things come together which have to be planned carefully…