How to clear calendar cache?
Just learned that the Library files are hidden in the most recent versions of OSX.  To see them, open Finder, then click simultaneously on the Go tab and the Option key.  As long as they are held down, a new item (Library) will appear.  Go down to it and you will find your file.  Or you can open Finder, select the Go tab, then the Go to Folder item, and insert ~/Library.  Not exactly user intuitive.  Unfortunately, Apple is becoming more like Microsoft in terms of usability.