clockless workern.
An employee who is willing to work at any time, day or night.
Earliest Citation:
It was late Sunday night when I called my team in for an impromptu meeting. I was sure they wouldn't mind - after all, I had been training them to be clockless workers, and of course they were all team players.
Alan Rooks, "A Christmas paradigm," North American Papermaker, December, 1997