In my days at Heathrow, back in the eighties, we once had a posse of light singles arrive, park and depart a while later. Believe me, this was considered by all on the ground as a big imposition - we felt we had to be there for the flights actually scheduled -
At many places ATC is a 24/7 job. Of course you're meant to be there if it falls on your rostered days, it's your job. There is always the alternative of going non operational and working 9-5 with the suits and thus guaranteeing your Xmas Day off if you feel it's that much of an imposition
And being the 80's, I bet none of you who worked complained about the triple time you probably received. Thought not
