Christmas

[Barry]

No: HPFGUIDX 167200

I've just been rereading HP and the Order of the Phoenix. There's a 
chapter where the Weasleys and Sirius are celebrating Christmas. Two 
things struck me.
1. Would witches and wizards celebrate Christmas? Wouldn't they have 
their own (more ancient?) holidays?
2. Mr Weasley, in particular, delights in Muggles' devices because he 
seems so cut off from the muggles' world. Would he even know about 
Christmas? Or he'd know about it in much the same way as the average 
Christian knows about Passover.

Any comments?
Thanks
Barry