Show HN: Callibella – Sync personal calendar to work calendar, privately

Callibella is a small util that reads the events on your personal calendar, and then goes to your work calendar and places "busy" events at the same times. It maintains this one-way sync - updating and deleting events if they changes in your personal calendar, and it doesn't reveal the actual data of your events.

It uses CalDAV behind the scenes, so it's easy to use with any calendar provider, it runs 100% locally (so you can put it behind some cron job and forget about it), and it is as easy to run as `npx callibella`!