Midnight, an idiom in China, means that there are five classes in one night, and the third class is midnight. It means late at night. From Ma Yuan Zhiyuan's Tears of Shirts, the third fold: "Who is on this boat, yelling in the middle of the night?" . There used to be five classes in one night, each class lasted about two hours. Late at night, about twelve o'clock. Late at night means late at night.
The way of timing in ancient times is very different from that in modern times. A day is divided into twelve hours, each of which is different in length. Among them, one, two, three and three are in the evening, four are between childhood and Shi Mao, and five are between Shi Mao and You Shi.
It's midnight19: 00–2100. People will light candles at home and enjoy the peace of the night. Second, it's 21:00–23: 00. At this time, the night is deeper and everyone has a rest. Only some people who walk at night will walk in the street.
Midnight is 23:00-0 1:00, which is already late at night, and many people have fallen asleep. Only some people who are on duty or stay up late at night will be active at this time. The fourth watch is 01:00–03: 00. It is already early in the morning, and the sky begins to turn pale slightly. Some early risers will start preparing breakfast or go out to work at this time.
It's 03:00-05:00 Yin Shi time, the fifth watch. It's dawn at this time, and people are busy, doing housework, labor, production and so on. In the ancient south of China, people often lit oil lamps at dusk, so the first shift may be advanced to six or half past six.
In Han Dynasty and Tang Dynasty, a day was divided into three grades: hour, hour and second. Time is equivalent to two hours now, a quarter is equivalent to fifteen minutes now, and a second is equivalent to sixty seconds now. In addition, there was a practice of dividing a day into twenty-four hours in the Ming Dynasty, and each hour was equivalent to one hour now.