Editable Calendar for Holidays

As much as I would like to edit my holiday calendar you can't. It would be nice to download or create a calendar on our own. Since neither is available what I might do is go through the year and add events for each holiday I want, make it "Important" or red and then delete this U.S. Holiday calendar. Along with others I'm tired of way too many items showing up I've no need to see or know about. Not a holiday to me or ever will be and not important to me at any level. Apples calendar has always been short on features as is most of their stuff.