Okay, this is a rather simple question, but since my sister stole my copy of OotP and took it to school today, I can't look up the answer.

In OotP, Hermione goes skiing with her parents at the start of the Christmas holidays, but a short while later she arrives at Grimmauld place, saying that skiing isn't her thing, and that she'll be staying for Christmas. Well, what I was wondering was whether Hermione had already gone on her holiday with her parents when Harry had his vision about Arthur getting attacked by the snake, or if the school term hadn't completely finished at that point. And then, how long after Arthur's attack did she arrive at Grimmauld place?

Thanks.