Is it your birthday to be 73 or 84?

The reason why the prince was uninvited for seventy-three or eighty-four days was mainly related to Confucius and Mencius in the history of China.

Confucius and Mencius are the founders and developers of Confucian culture. Since the Spring and Autumn Period and the Warring States Period, Confucian culture has had a far-reaching impact on society. In the Han dynasty, the policy of ousting hundreds of schools and respecting Confucianism alone established the status of Confucianism. Confucius, the founder of Confucian culture, lived to be 73 years old and Mencius, the master, lived to be 84 years old.