CalendarMate

I run my life across four calendars. Two work, two personal — one of which is Proton. I care a lot about where my data goes, and Proton is a deliberate choice, not a default.

So when I needed to share my availability and let people book time with me, I went looking for the obvious solution. Calendly, Cal.com, the usual suspects. Every single one wanted me to connect my calendar via OAuth. Hand over access. Trust them with it.

For my Google calendar, maybe I'd have held my nose and done it. But for Proton — the whole point of Proton is that you don't hand it over to anyone. That's why I use it.

There was nothing that worked across all four calendars without either asking for OAuth or just not supporting Proton at all.

Two decades ago I was an amateur developer before moving into management. I don't write production code day-to-day anymore and haven't for many years - back then I was building websites that proudly displayed "Best viewed in Internet Explorer 6"; Things have changed a little since then! But I still think in systems — and the solution here was obvious. Every one of those calendars exposes a read-only ICS feed. No credentials. No OAuth. Just a URL. Someone should have built a clean booking tool on top of that years ago.

Recent AI coding tools meant I could actually build it myself in evenings without it taking over my life. So I did. CalendarMate reads your ICS feeds, shows your real availability, and gives anyone a clean link to book time with you. Your calendar stays yours.