Calendar "sync"

I have calendars on multiple systems with different people relying on free/busy for only their system. I can’t move them to a 3rd party scheduler because I am the only person with this problem in their large multi person meetings.
As you can imagine this is a very manual task to avoid double booking especially as I don’t want details leaking between systems only availability.
I would love to automate this!

So if there’s an event in calendar A create a “busy” event in calendars B and C

Where are your calendars hosted?

I’m guessing Zapier or Integromat would probably be able to do this if you are using an appropriately connected host platform.

yeah, cloud services are out. Mix of cloud and on prem. (and fantastical) on mac or ios is the only “touch” point

So just to clarify, these three calendars are not hosted anywhere that syncs them between macOS and i*OS. They are local only calendars on independent devices, or hosted on an internal network with no external access for cloud services.

Sorry, my calendar applications can access/sync all the calendars. But they’re not cloud reachable, no. I was thinking applescript on the mac or perhaps a shortcut that runs when i open calendar on my iphone/ipad (as i do open that frequently)

Maybe you could periodically scan calendars from your Mac using icalBuddy and anything that isn’t on a master calendar, gets added to that, and then to any calendar that isn’t the one the entry was found on.

You could also run a reverse method to remove deleted entries.

I would suggest having some sort of indicator in the master calendar to let you know which calendar the event originated on. This could optionally be included on the receiving calendars too.

thats the most promising, though the age of icalbuddy is a little worrying!