@BKeyport thanks… I see an other change submitted today
https://github.com/MagicMirrorOrg/MagicMirror/pull/4180
which references this topic
if you want to try that do
cd ~/MagicMirror
# restore calendar.js
git checkout defaultmodules/calendar/calendar.js
git fetch origin pull/4180/head:_fix_304
rm package-lock.json
git switch _fix_304
npm run install-mm
restart MM