"Seamless" Android calendar sync with davical's own server

Question

Android

Hey!
It has its own CalDAV server based on davical. There are a bunch of devices on the Android platform.
In Android, it is possible to add your own calendar server, but for some reason it is not added out of the box - check the server settings. I read that there are some client synchronizers that are installed on the device and synchronize caldav calendars with Google's.
Actually the question is - what kind of tricky protocol does the Google calendar use and is it possible to somehow add another calendar that will be targeted to our davical server without any undue tricks?
Ps Maybe all of them have a description of the Google calendar protocol that expects to receive an android device .. then I would write a server connector to davical