If the brush is used for calligraphy, the signature is generally in the traditional format. Signature can have a deposit. Common only the next paragraph, the format is:
Time (usually not Gregorian calendar)+(%location)+author+(respect) book
Such as: "Xin Chou Zhong Qiu XX respect book".
In traditional calligraphy, dates are marked by years, and months are marked by lunar calendar, not specific to a certain day.
Hard-pen calligraphy, if arranged horizontally, can be in a modern format: 202 1 year1October, X, XXX book. If it is vertical, it should also be in the traditional format.