(He's an agnostic vegetarian, just for a bit of background. He also loves Christmas - he says he's almost done with present shopping, and I'm still trying to figure out what to get everybody.)
So, I leave it to the Fine Folks of The Question Club.
When is the earliest a Christmas tree should go up?
Anytime after Halloween
Anytime after Thanksgiving
Never - I don't do Christmas trees for whatever reason
Never - I keep mine up all year long
Up Christmas Eve, down Boxing Day
Another answer I'll mention in the comments
Where are the ticky boxes, bitch?
I'm a vegan!