The Living Thing / Notebooks :

Calendars and contact databases, digital, use thereof

Google calendar, iCloud etc exist. but who wants to spend so much effort gifting google with free information about all their friends? Well, most of my friends, TBH. But it leaves me feeling gross.

Jargon to know here: CalDAV and CardDAV are the de facto standards to sync your calendar and contact information, respectively. All you need is a server which talks those standards and you can use whatever client you’d like. In principle.

So! Running your own. that’s a legitimate use of your precious free time, right? Uh.

The only contact syncing that works well with macOS is icloud (they claim to support any CardDAV server, but in practice that is nothing but glitches and failures.

Syncing

Evolution supports icloud interoperation. Possibly so do other Carddav options. There is an ios app Contact mover whuch brute-force synchronises icloud contacts to carddav servers.

Syncevolution is a full contact-syncing app which supports various CardDAV implementations with some restrictions.

Server

Client