(10-96) The earliest recorded history in China was Chou dynasty. According to the "Book of Li", the emperor has three madams, nine ladies, twenty seven house ladies, and eighty one imperial wives." These do not include the queen, and the concubines. Of course the queen has the highest status, and the concubines the lowest.

There is a strict schedule for these women. The eighty one imperial wives are responsible for the first nine nights of the month, according to the lunar calendar. The twenty seven house ladies are responsible for the next three nights. The nine ladies are responsible for the following night, and the three madams are responsible for another. Thus on the fifteenth night is the night of the full moon; it is the night for the queen.

The ancient Chinese believed the moon is the symbol of Yin. During full moon, the queen will be most ready to conceive. They also believed that man can replenish his qi from different young women. Thus, the fourteen nights before the full moon to get the emperor ready.

What a scheme for reproduction.