In Japan people clean their house in the end of the year. It’s one of customs and the purpose of it is to have a new year with a clean house.
The different with usual cleaning is that we clean many places where we usually don’t clean much; for example, windows including screens, ceilings, and so on.
It’s usually held around December 28th, but some people do it in a different day. It depends on their schedule.
I clean the house in the end of the day every year, and it is so nice and makes me feel refreshed for the next year.