Read the statement by Michael Teeuw here.
3 Appointments from 2013 Appear in Calendar Every Day
The Calendar module displays what appear to be all my current appointments [pulled from Google Calendar using the public .ics url].
In addition, every day at the top of the list are three that are not on my current Google calendar: one instance of one and two instances of a second. Both appear to have been weekly repeating appointments last used ~2013.
Since I don’t see them daily on the Google Calendar, nor on my Microsoft Outlook that is synced with the Google Calendar, I am stumped on how to troubleshoot this.
Never mind… I think i have fixed it for now. I went into Google Calendar in the browser, searched for each event and deleted all recurrences. Within a couple of update cycles on the MagicMirror the events disappeared.