Happy new year, everyone! Here's a story that isn't technically about the new year but doesn't fit anywhere else. It's from Kita Seiro 北静廬's Baien Nikki 梅園日記 ("Plum garden diary"), quoted in Inagaki Shisei 稲垣史生's Edo hennen jiten 江戶編年事典 ("Chronological Edo Encyclopedia"), on page 471-472:

Around the summer of Bunka 11 [1814], on a certain mountain in a certain province, a monkey spoke like a person, saying, "Many people have died of the diseases going around this year. If you put out a kadomatsu and eat zōni as if this year had finished and the new year arrived, you will surely be spared." Many indeed were those who did as instructed.

This, Inagaki notes, was known as hayari shōgatsu, literally something like "popular new year" or "new year as fad." This sort of manual fast-forwarding of a calendrical period judged inauspicious was actually not uncommon in Japan. For example, it was not unheard of for people finding themselves at a dangerous age on new year's day (because remember, back then everyone turned one year older when the year changed — the individual birthday had yet to be imported from the west) to celebrate new year's again on the first of the second month. Here's a paper in Japanese on the topic by Hirayama Toshijirō 平山敏治郎 with much more detail.

(I'm not sure how common it was to take medical advice from wild animals but I have a feeling it wasn't as rare as one might have hoped.)