There's an open request for a remote API for team calendars which would have enabled you to script it but it's not an option right now
You could right some external script that logged into the database and manipulated the data store but it would require Confluence to be down and it would likely break any time the data format changed.
I've been thinking about this as well as I've noticed the performance isn't great for large data sets. (caveat: I'm running an older version). Only way I could think about is to delete old calendars and roll onto a new one
Two vulnerabilities have been published for Confluence Server and Data Center recently: March 20, 2019 CVE-2019-3395 / CVE-2019-3396 April 17, 2019 CVE-2019-3398 The goal of this article is...
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event
You're one step closer to meeting fellow Atlassian users at your local event. Learn more about Community Events