Among the twelve hours in ancient my country, there is no Xuanshi hour. But when "Xuan" itself is used as a noun, it is another name for the ninth month of the lunar calendar, which is called Xuanyue. So the Xuanshi here refers to the Xuan month, which is the ninth month of the lunar calendar.
The term "Xuan Yue" comes from Zuo Qiuming's "Guoyu Yue Yue Xia": "As for Xuanyue, the king summoned Fan Li and asked about it." The author's birth and death years are unknown.
Explanation: In the ninth month of the lunar calendar, the king summoned Fan Li to ask him some questions.
Extended information:
The twelve hours in ancient China:
1. Midnight hour (twenty-three to one o'clock)
Ancient Chinese people discovered that the most frequent time for rats was Zishi. Therefore, Zi Shi was associated with the rat and became "Zi Rat", ranking first in the zodiac according to the beginning of the day.
2. Chou time (one o'clock to three o'clock)
Farmers use cattle to plow the fields, and feeding the cattle well is a major event for the farmer. During ugly hours (one to three o'clock), farmers will get up to feed their cows. When cows are associated with ugliness, they become "ugly cows".
3. Yin hour (three to five o'clock)
From three to five o'clock in the morning, the nocturnal tiger is the most ferocious. Farmers often hear the sound not far away at this time. There was a roar of a tiger. Therefore, the tiger was connected with the Yin time, and "Yin tiger" came into being.
4. Mao Shi (five o'clock to seven o'clock)
At dawn, the rabbit runs out of the nest to eat the dewy grass. Therefore, the rabbit was connected with Mao Shi, and "Mao Rabbit" came into being.
5. Chenshi (seven o'clock to nine o'clock)
Seven o'clock to nine o'clock is the time when fog is easy to occur. Dragons are the product of people's imagination and cannot be seen in reality. Only in heavy fog can people have the illusion of dragons. In this way, the dragon will "appear" in the fog of Tatsuki. Dragon and Chenshi are connected, and "Chenlong" is born.
6. Sishi (9 to 11 o'clock)
The heavy fog dissipates and the sun shines in the sky. Snakes with unstable body temperatures crawl out of their caves to bask in the sun. This is the time when snakes are most active. Therefore, "Si Snake" is naturally connected.
7. Noon (11 o'clock to 13 o'clock)
The scorching sun at this time reminds people of the horse, one of human beings' best assistants. The red-maned horse is a good horse, but its temper is as fiery as the sun at noon. The horse is connected with the noon time, and the "noon horse" comes into being.
8. At noon (13:00 to 15:00)
At noon, the scorching sun has dried the dew on the grass, but don’t forget that this is the best time to herd sheep. time. Thus, "Weiyang" came into being.
9. Shenshi (15:00 to 17:00)
The sun is westward, or the sky is clear after rain, and the weather becomes refreshing. At this time, monkeys like to play and cry in the woods. People hear this and remember it in their hearts, so they associate this moment with the monkeys, hence the name "Shen Monkey".
10. Youshi (17:00 to 19:00)
The sun is about to set, and it’s time for the domestic chickens to return to their nests; if they don’t return to their nests, they will be missing when it gets dark. . The farmer's wife was anxious, calling around, calling for the chickens to come into their nests. This time of eating and drinking is also connected with the time when chickens come into their nests, hence the name "unitary chicken".
11. Xu Shi (19:00 to 21:00)
People have to do a patrol before going to bed. Following them is another assistant of human beings - dogs. . When patrolling, it is just right to associate the dog with a dog and become a "dog."
12. Haishi (blackjack to twenty-three o'clock)
You can hear the sound of fat pigs troughing in the trough late at night, and the owner is very happy. But if you want the pig to grow fat, you have to feed it. The time of Hai is naturally connected with pigs, hence the name "Hai Pig".
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Baidu Encyclopedia-Twelve Hours