I also wish all of my data was version controlled, which is why when I created EteSync[1] I made sure to include a full change history. Check it out, I think it's exactly what you're looking for, and it's fully open source, so you can host in on-site if your company requires that.

https://www.etesync.com

Can that do shared calendars? (I know that's technically challenging with ETE encryption). If it does, I will drop my self-hosted davical for it in a heartbeat.

I found this in the FAQ:

If I want to share a calendar with my spouse, do I need to get two subscriptions? No. You can just create a normal subscription for yourself, and an "Associate" subscription for your spouse. Then share the calendar with the second account, and that's it. However, Associate accounts can't create their own calendars. So in order to have a personal calendar (that you can't see), your spouse will have to get a normal subscription too.

Yeah, it does. You just need to manually verify each member you add to make sure they are trusted (or alternatively just YOLO).

I will take a look! I'm looking to further distance myself from Google and such this year, so this is very timely.

I had exactly the same thought, it's kind of an interesting idea. I'm not 100% sure what the usefulness is though.

I suppose it depends on how much content you put in your calendars, but I agreed with you on the usefulness, at first.

Then I thought about how meeting requests are basically PRs. How how easy it could be to create shared calendars using submodules and such.