Keeping the focus

Something I always wanted to is how to keep student active near the end of the year or around holiday times like Christmas. I know you can do activities centered around the holidays but lets be honest when I was in school and we were doing those activities i was only thinking of not being in school. So do we just keep doing these activities or try to just remained focused on the topics? I remember thinking in the classes that stayed on topic i was more annoyed and not focused on the work. It was just a curious question I had and wondered peoples thoughts on the topic. I just think that it can be hard to do as a teacher knowing yourself that it is the holidays and it is suppose to be fun. It is halfway through the year so it can't hurt to let them have fun for the time of the year it is. Also to show them that school can still be fun when we learn is something else teachers do at the holidays. But the question to me still is, how should we keep kids focused around holidays and mid year breaks?