"Merry Christmas and Happy New Year!"
Translation:God jul og godt nyttår!
"Glade jul" is a Christmas hymn, but no: Norwegians say "God jul".
According to this [ http://tux.aftenposten.no/spraak/spraak?action=questionid=2184 ] language related column in Norway's largest newspaper, the rule used to be "God jul" before Christmas and "Gledelig jul" during Christmas.
However, that is archaic and these days most people use only "God jul".