DAViCal is a server for calendar sharing. It is an implementation of the CalDAV protocol which is designed for storing calendaring resources (in iCalendar format) on a remote shared server.
DAVx⁵ settings
Base URL: /caldav.php/<your.user.name>/
(e.g. https://your.server/davical/caldav.php/exampleusername/
)
Contact group method: groups are separate VCards (or the method used by your other clients)
Configure well-known URLs so that you don't have to enter the whole path (recommended).