I found a posting here that explained how to clear all events from a specific calendar by going into calendar Options (i.e. not requiring Desktop Manager).
Now I cannot remember nor find the keyboard shortcut that could do this.
Does anyone know?
No. There was a key combination that, when pressed, would clear the highlighted calendar and attempt to re-download the calendar (if it's seup for syncing).
I ended up just doing it over Desktop Manager but it would be awesome if someone posts the shortcut.