I'm trying to teach my English husband about this :). I grew up in a part of Sweden where ST Knut's day (Tjugondag Knut) was the official end of Christmas and celebrated at times with a 'julgransplundring' - a party for children in the area, when you had a last dance around the tree before you 'plundered' it of all edible decorations and then danced it out of the house singing the song Felipa posted above. A julgransplundring was almost as much fun as a Christmas party if you're a kid, and at least in my home we had to take strict turns smashing the gingerbread house. My father and grandparents on his side are from Norway and they had the same tradition in his home when he was growing up - I strongly suspect that what matters is not if you're from Norway or Sweden, but where you're from in Norway or Sweden (or Finland, I know at least some parts of Finland keep Tjugondag Knut as well). I have Swedish friends who had never even heard the words 'Tjugondag Knut' before I talked to them about it.