Yes, I know it sounds extremely trivial and it probably has been asked many times before, but I can't seem to find the information anywhere. If this thread has already been created, then I'm sorry. It is not my intention to spam.

Does anybody know/remember when is the first trip to Hogsmeade made during the school year?

I know there's a specific date given in POA, but I can't remember and I don't have my books with me.

And also, how often are those trips made?

Thank you.