Is there any official religion not celebrating around Christmas time?

I'm non-religious and that's an Official Religion (tm), so yes there is. I choose to do Festivus this year because I've had enough of the gross-overcommercialisation and I reject all religious undertones.

What's an official religion? Is there a universal definition? In this country religions can qualify for government support so I suppose that those are in some way official but there must be some that either don't qualify or haven't sought the money; does that make them unofficial? If so what does it mean?

I don't think Islam has anything at this time. There may be others that don't. Observing the solstice in one way or the other does seem to be almost universal. The majority do.