The funny thing is that Gabriel, who's usually such a stickler about these sorts of things, had a change of heart when the Nativity started picking up more local trends. It coincided exactly around the time when that carol was written about him.
[Crowley]
None of them are, my dear.
Oh. Alright. Good to know.
You probably wouldn't be into doing some celebrating before then? What am I thinking? It'll be against your nature.