Sync your calendars without sharing the details.

You keep multiple calendars, like work and personal. But real life overlaps, especially when you work remotely.

Someone tries to book you at 3pm. Your work calendar says you’re free, but your personal calendar says you’re not. Now you’re double-booked and have to sort it out.

You can keep your calendars manually in sync, but that wastes time. Or you can share all your calendars with your coworkers. But then they know everything about your personal life: the uncomfortable doctor’s appointment, the divorce lawyer meeting, or anything else you’d rather keep private.

buoycal gives you another option: share when you’re busy, without sharing why.

buoycal reads your source calendars and writes blocks to your destinations. A meeting titled “Acquisition sync — Project Falcon” lands on the other side as a block that says Busy: the right time, nothing else.

It works with Google Calendar, Microsoft 365 and Outlook, and any standard CalDAV server, like iCloud, Fastmail, Nextcloud, or your own. One-way, both ways, many-to-one: you decide which calendars feed which.

You decide which events count, too. Plain when/then rules: when an event is all-day, skip it; when you declined, no block. Only the times that matter are written.

Titles never reach the other calendar. That is the default and the only behavior: there is no setting that writes your titles into a destination. A rule can read a title to decide whether an event counts; what gets written stays a block.

Self-hosted, your event titles never leave your machine. Hosted, a title is held in memory only long enough to compute the block. It is never written to disk, logged, or sent on. What we store is a time and the word “Busy”. If you’d rather it never touch our servers, buoycal is open source; run it yourself.