Why should firecrackers be set off on the eighth day of the Lunar New Year?

The reason why firecrackers are constantly set off on the eighth day of the first lunar month is that many merchants set off firecrackers on the eighth day, hoping to win a "good omen" for the year.

I believe everyone has heard the story of Nian Beast. According to legend, in ancient times, in order to drive away Nian beast, people would light lights, set off firecrackers, and scare away Nian beast with firecrackers, thus ensuring a year's peace.

There is such a legend, not groundless. According to ancient records: "On the first day of the first month, chickens crow and firecrackers are set off in front of the court. It can be seen that on the first day of the first month in ancient times, people would set off firecrackers in front of the court at dawn when the rooster crowed, and the initial function of firecrackers was to eliminate disasters.