The new year... A celebration of time going forward. Even if it's gone backward, or something, Sans does like the idea in spite of himself. In spite of himself, because it's not like time is normal here, they missed November, he can hardly remember October. But, well.

"Hey, I'm always up for an excuse to eat more food. I've got a pretty bad habit of fallin' asleep before midnight gets here, though."

But this time maybe not. Just to see things go forward. (He'll be disappointed, later.)