CalendarAgent showing excessive CPU use

So every once in a while I will see my CPU usage go up high on all 4 cores for a while. Usually more than just a few sec, but rarely longer than for a minute.

Turns out it’s CalendarAgent. This is on HS, using both iCloud (personal) and Google (work) calendars. Anybody else see this regularly? Anything to stop it?

I should probably also mention Calendar can be real slow to launch sometimes (not always) and in other cases it’s really slow about adding a new event or modifying an existing one. Communication issues with the mothership maybe?