Kala Xristouyenna!
In Greece it's a solemn holiday with gift exhange and continues until Epiphany on January 6th.
On the day and evening before Christmas and New Year's, children sing the equivalent of carols (kalanda) from house to house. These kalandas bless the house. To hear some go to
http://kypros.org/Occupied_Cyprus/epiktitos/video/video.htm
and go down to CAROLS FROM GREECE AND CYPRUS
Beautiful!