There is a time skip, but if you have things still to do, it doesn't work. There is an algorithm that checks if you have completed some event chains or not, so it doesn't interrupt what you are doing.
The truth is that it was a very experimental update, and it is almost impossible to predict in which order you have played the events or which stories you are advancing or which ones you are not. But I wanted winter to come organically to the game and not make a Christmas event that comes out of nowhere and has no relation to the main story.
My recommendation is not to skip days until December, but to finish the content you have unfinished.