They danced ECDs, they didn't go to an EVENT called an ECD. They went to a 'dance', or a 'barn dance' and now are going to 'ceilidhs'.
I showed you that wiki link way back at the start of the thread. It says that ECD is a dance form, not an event, so insisting on calling events ECDs is silly.
Now find me a source that says that the event is called an ECD.