US Holidays calendar has been hacked
The US Holidays calendar seems to have been hacked. If you follow the instructions for subscribing to holidays using the Language and Regions Preference panel and Calendar Preferences, the resulting US Holiday calendar shows more than US Holidays, it includes phases of the moon and has errors, for example: 2 March displays "Holi"
Is there a better source of holidays?
Mac mini (Late 2012), macOS High Sierra (10.13.1)