In modern life, the 24-hour time system is used, taking 0 o'clock as the boundary between two days. After 24 o'clock, it enters the next day, which is convenient for recording and expressing.
However, in ancient times, 11 PM was considered the boundary between two days. The midnight hour included two time zones: 11 PM to 12 AM of the previous night and 12 AM to 1 AM of the next day. Therefore, to make it easier to distinguish, it was divided into early midnight hour and late midnight hour. Early midnight hour refers to 12 AM to 1 AM, while late midnight hour refers to 11 PM to 12 AM.

A folk saying goes that "a thousand golds cannot buy four taels of fate," and "even immortals cannot predict the fate of the midnight hour." This is because the midnight hour is a special time period. In the hours before and after midnight, a slight mistake can lead to a difference of one day, and thus a completely different fate. However, people born during the midnight hour are said to have very good fates.
People born during the midnight hour have the zodiac sign of rat water. Rat water is one of the four central positions, so those born during the midnight hour have an excess of water in their birth chart. Moreover, the midnight hour is a time of transition between day and night, the moment when yin reaches its peak and yang begins to arise. Therefore, people born during the midnight hour are generally smart, quick-witted, handsome, and considerate. However, they often receive support from their ancestors and their spouses, making it easy for them to achieve success at an early age, and they also tend to live longer.