After the Song Dynasty, every 20 hours were divided into two parts, namely, early childhood, early childhood, early ugliness, and early ugliness ..... In turn, it happened to be 24 hours, which is consistent with the current 24 hours a day.
In the Han Dynasty, it was named Midnight, Crow, Pingdan, Sunrise, Food Time, Horn, Japan-China, Sundial, Sunset, Dusk and Man's Decision. It is also expressed by the twelve earthly branches, and it is the child time from 23: 00 to 1 at midnight, the ugly time from 1 to 3: 00, and the Yin Shi time from 3: 00 to 5: 00, which are recursive in turn.
12 hour clock
It was used in the Western Zhou Dynasty. In the Han Dynasty, it was named Midnight, Crow, Pingdan, Sunrise, Food Time, Horn, Japan-China, Sundial, Sunset, Dusk and Man's Decision. It is also expressed by the twelve earthly branches, and it is the child time from 23: 00 to 1 at midnight, the ugly time from 1 to 3: 00, and the Yin Shi time from 3: 00 to 5: 00, which are recursive in turn.
Twelve o'clock consists of twelve specific time nouns. People can find the source of these words from the ancient books of China in the pre-Qin period. Before the Han Dynasty, these appellations were different. Until the early Han Dynasty, China implemented the taichu calendar Law. "Twelve o'clock a day, the main branch is the subject."