How do I make a real time timer that lasts over an entire week?

I'm developing a game and planning on an event occurring for a given holiday. Is here a function where you can check the current date and time and see whether or not it passed the date of the holiday?

For example, let's say that I set it up so I gave the date in days month year format of Christmas and it would return a boolean statement if christmas already happened. Thank you.

Yes, check out os.date and os.time, here's a relevant PIL chapter.