How to get 2 Christmas Days and 2 New Years Days

So I bought my tickets and my apartment for my stay in Belgrade. I'll be arriving in Belgrade on January 7th and leaving on February 7th. I just learned that Serbians celebrate Christmas on January 7th and New Years Day on January 13th/14th. This means I'll get 2 Christmas Days and 2 New Years Days this year!

And from what my friends in Serbia tell me, both celebrations involve a lot of drinking! I know what I'm doing this month for January!