In northern China, Little New Year falls on the 23rd day of the twelfth lunisolar month.
Little New Year, or Xiaonian, is a preparation festival held roughly a week before Chinese New Year. It is closely associated with the Kitchen God, who is believed to leave for Heaven around this time to report on the household’s behavior to the Jade Emperor.
The date is regional rather than universal. Northern Chinese communities traditionally observe Xiaonian on the 23rd day, while many southern communities observe it on the 24th. That regional split is the main reason the 24th day can seem plausible, but it is not the canonical answer when the question specifies northern China.
Traditional observances include cleaning the home, preparing New Year foods, burning or replacing an image of the Kitchen God, and offering sweets. The festival should also not be confused with Chinese New Year itself: the first day of the new lunisolar year comes later, followed by celebrations that traditionally culminate with the Lantern Festival on day 15.