When was New Year's Day in ancient China?

A: On the first day of the first month.

New Year's Day in ancient China refers to the first day of the first month of each year. The word New Year's Day means the first day, that is, the beginning of a year. However, although the meaning of the word New Year's Day has not changed, the days of each dynasty are different. For example, the Shang Dynasty was the first day of December and the Qin Dynasty was the first day of October. It was not until Emperor Wu of the Han Dynasty that it was officially unified as the first day of the first month.