The “Formative” slug here identifies Davis, a CardDAV and CalDAV server. Connect the clients your team uses, create a contact and event, then edit them from another device. Check conflict handling, recurring events, time zones, and what happens when a device has been offline.
Self-hosted synchronization needs backups and access controls. Export contacts and calendars and restore them to a clean instance before moving personal data. Judge the service by reliable cross-client behavior rather than an empty-server setup screen.
Akousa