I need to add booking to my website. I stumbled upon cal.com which seemed great. However I’ve run into 2 issues.
My current options for calendars are Protonmail and cpanel/webmail/roundcube.
cal.com doesn’t really work with either of these. For proton its mostly on proton’s side, their calendars are read-only externally + a bit buggy: https://github.com/calcom/cal.com/issues/5756
Roundcube uses caldav, and cal.com’s support is still in beta with most caldev’s being unsupported: https://github.com/calcom/cal.com/issues/3457
Roundcube got me the farthest but the booking emails just don’t get sent and the calendar event pops up maybe an hour later + there’s 75% the booking just doesn’t work. I was told this was the calendars fault 😂.
SO
Are there any selfhosted calendar implementations that support ics feed, external viewing ,etc etc that I can throw on a standard webserver?
Or are there any better foss booking systems?
I just need to book clients and connect it back to a working calendar that’s not locked to a desktop. I thought this would be a solved problem in 2026…
I’m not trying to pay for yet ANOTHER software on top of business mail, and a webserver.
Thanks.


So you are asking about something that seems simple, but is actually many different components working together. Apple and google have really made this integrated for a long time.
What you want is:
I’ve left out all the plumbing needed to either support your access to this, or provide secure integration with a 3rd party email service.
This is a hard problem to solve for self-hosting. I have a self-hosted radicale instance and I get around the inter-connectivity by simply exporting ICS files and sending them to folks. Updating meeting times, setting calendar sharing is all very difficult because of above.
Maybe I’m misunderstanding, but you’re saying shared/sync’d and updateable calendars outside of big tech like google is still an unsolved problem?
Sorry, I didn’t mean to doom that answer.
It is possible, but it is complex and onerous. How much appetite you have for that is of course up to you.
The basic functionality of hosting my own caldav/cardav fully privately with synchronising across devices is enough for me.
I’ve been looking into this a bit already. I’m actually on a road trip and will start driving soon, but if your respond to this comment I can fill you in on what I’ve learning in the next day or two.
never hurts to learn.
Took me a while to get back to this. I got a bit sick over the weekend. Anyway, the opensource scheduling software is not too great. I am a little surprised by it as there are a few commercial options or opensource options that lock certain features behind a paywall even when selfhosting, like cal.com.
Cal.com is the only software that provides the feature set I need, but they charge about as much per user as Zoom does and it pisses me off that it’s so expensive to have a shared calendar so my clients will simply book a time and date and have round robin logic applied to who the client gets assigned to.
Because of this, I am slowly working on building my own scheduling system that I will selfhost. I am mostly vibecoding it as I am too busy running a small company to dedicate time to coding it properly, but that is some tech I can easily test for functionality and fix down the line when there is more time or money.
simplybook.me is another service I came across, but they charge you based on how many features you enable, and you basically can’t use their system for scheduling without adding on a bunch of features. Once your trial ends, you can’t turn off the features and go back to the free version without signing up for a pro account or whatever they call it.