The ancients divided a day and night into twelve periods, and each period was called an hour. Twelve o'clock can refer to either a day or any time. Twelve o'clock was originally created by the ancients according to the natural laws such as the appearance and appearance of the sun, the change of the sky and their daily production activities and living habits. Twelve o'clock consists of twelve specific time nouns. People can find the source of these words from the ancient books in the pre-Qin period. Before the Han Dynasty, these appellations were different. It was not until the early years of the Han Dynasty that taichu calendar Law was implemented in China. "Twelve o'clock a day, the main branch is the subject." (Zhao Yi's Examination of Jade Cong, Volume 34) Basic stereotypes and naming. The twelve o'clock clock is unique and has a long history. It is an outstanding contribution of the Chinese nation to the astronomical calendar of mankind and one of China's splendid cultural treasures. Day and night are divided into twelve hours: Zi (zǐ), Ugly (chǐu), Yin (yín), Mao (m ǐ o), Chen (chén), Si (s), Wu (), Wei (wèi) and Shen (shēn). From 9: 00 to 1 1,1to 13, 13 to 15 to 17,/kloc-0. 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. 2.24-hour system. 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. 3. Ten-hour system. Appeared in the pre-Qin period. Five minutes during the day and five minutes at night. According to Tian Wenzhi of Sui Shu, the days are morning, evening, noon and evening, and the nights are A, B, C, D and E (later represented by Wu Geng). 4. Five-hour system. Its names are Chen Ming, Yong Ming, Dan Ming, flea (early) food, banquet (late) food, corner, center, less return, shop time, big return, high return, low return, county (hanging) east, dusk, and ding faint. See Huai Nan Zi. Astronomical training. 5, a hundred minutes. That is to say, day and night are divided into a balanced one hundred quarters. Its production is related to the use of missing prints. May have originated in Shang Dynasty. In the Han Dynasty, it was changed to 120, and in the Southern Dynasty, it was changed to 96, 108. After many twists and turns, it was not until the introduction of European astronomical knowledge in the late Ming Dynasty that the reform of 96 engraving books was put forward and made it a formal system in the early Qing Dynasty. 6. Ancient times did not necessarily have strict temporal significance, but there were quite a few common and commonly used names. Generally speaking, sunrise can be called Dan, Zao, Chao and Chen, and sunrise can be called evening, dusk and evening. When the sun is in the middle, it is called noon, noon and pavilion noon, when it is near noon, it is called angle, and when it is west, it is called day. After sunset, it is dusk. After dusk, it's up to people. After a person is appointed, it is midnight (or midnight). After midnight, the chicken crowed. After the cock crow, it is ignorant and dull-this is the time when it is already dawn. The ancients had two meals a day, and the last meal was before sunrise, which was called eating time or eating early; After sundial, before sunset, it is time to have dinner. This time is called "time". Midnight, also known as midnight and midnight: the first hour of twelve o'clock. (23: 00 to 0 1 hour Beijing time). Ugly cock crow, also known as pheasant: the second hour of twelve o'clock. (065438+ 0: 00 to 03: 00 Beijing time). Yin Shiping Dan, also known as Dawn, Dawn and Sundan, etc. Time is the alternation of day and night. (03: 00 to 05: 00 Beijing time). Sunrise in Shi Mao, also known as the beginning of the day, dawn and rising sun, refers to the time when the sun just appeared and Ran Ran first rose. (05: 00 to 07: 00 Beijing time). Eating in the morning is also called breakfast. The time for the ancients to "eat in the morning" was also breakfast time (07:00-09:00 Beijing time). Forty holes, also known as Yu Ri, etc. : near noon, call the corner. (09: 00 to 1 1: 00 Beijing time). Noon, also known as sunrise, noon, etc. : (Beijing time 1 1 to 13). Not long ago, it was also called sunset, sun center and so on. : The sun sets in the west. (Beijing time 13 to Beijing time 15). Feeding at the time of application, also known as day shop, late food and so on. (Beijing time 15 to 17). As time goes by, it is also called sunset, sunset and evening: it means when the sun goes down. (Beijing time 17 to 19). Dusk, also known as sunset, sunset glow, dusk, etc. At this time, the sun has set and the sky will be dark. The world is dark and everything is hazy, so it is called dusk. (Beijing time 19 to Beijing time 2 1). At this time, it was already late at night, and people stopped their activities and had a rest. Calm means quiet. (Beijing time 2 1 hour to 23: 00). Time-the twelve hours of a day in the Chinese zodiac: the first half of the night is 1 1 to 1, the second half is 1 to 3, the second half is 3 to 5, the second half is 5 to 7, and the second half is 8 to 7. 1 1 pm is noon, 1 pm is inappropriate, it is silent from 7: 00 pm to 9: 00 pm, and it is Shihai from 9: 00 pm to 1 1 pm. It takes two hours every hour. It can be seen that "from the fourth hour to the last hour" is equivalent to "from 9 am to 3 pm" now. More-in ancient times, it was regarded as a watch at night, a watch at sea, a watch at home, a watch at home, an ugly watch, and a watch from Yin Shi. There are five classes at night, and drums are played according to the class, with five points for each class. One hour per shift is equivalent to two hours now, which is 120 minutes, so each point in each shift only takes 24 minutes. It can be seen that "cooking at four o'clock and sailing at five o'clock" is equivalent to "65438+ cooking at 0: 00 to 3: 00 in the middle of the night and sailing at 3: 00 to 5: 00". "5: 00 and 3: 00" are equivalent to 5: 00 and 72 minutes in the morning, namely 6: 00 and 12 minutes, and "3: 00 and 4: 00" are equivalent to 1 and 96 minutes at midnight, namely 2: 36 minutes. Sculpture-Ancient time was measured by clepsydra. The leaky pot is divided into two parts: the sowing pot and the receiving pot. The seeding kettle is divided into two or four layers, both of which have dripping holes, and finally flow into the receiving kettle. The kettle has an upright arrow engraved with 100 minutes. The arrow gradually rises with the storage of water, showing the number of minutes to show the time. And a 24-hour day and night is 100 minutes, which is equivalent to 1440 minutes now. It can be seen that each moment is equivalent to 14.4 minutes now. So "3 noon" is equivalent to noon 1: 43.2. The ancients divided the evening time into five watches, and one watch is equivalent to two hours now. From 7: 00 pm, one table refers to 7: 00 to 9: 00, another table refers to 9: 00 to 1 1, the third table refers to 1 to 3: 00, and the fifth table refers to 3: 00 to 5: 00. The ancients divided a day and night into 12 hours, expressed by 12 earthly branches, and each hour is equal to two hours in modern times. Comparison between ancient and modern times: from 11: 00 p.m. to 1: 00 a.m. the next day, from 1: 00 to 3: 00 in ugly times, from 3: 00 to 5: 00 in Yin Shi, and so on. Every two hours are Shi Mao, Chen Shi, Shi Si, Noon, Weishi, Youshi, Xushi and Shihai. The largest number before "Geng Tian" is five, which means from three to five. China Ancient Unit 1. Time: refers to time. In ancient times, a day was divided into 12 hours. As the name of time, the earthly branch has an ancient customary name. The beginning of an hour is midnight. Gu "Rizhilu": "Since Han. The calendar is getting closer and closer, so the day is divided into twelve o'clock, and I don't know who started it, but it has not been abolished so far ... However, what is said about midnight is the so-called children's time, the crowing is ugly, the flat feet are ugly, and the sunrise and sunset are ugly. At noon, people eat in the corner, but not at noon. A day is divided into twelve, and only here. " In the Northern Song Dynasty, every hour was divided into two parts: the beginning and the right. Twelve hours are divided into twenty-four hours, which are called "hours". Second, lettering: About before the Western Zhou Dynasty, the ancients divided the whole day and night into 100 lettering, and carved 100 squares on the leaky cauldron axis. Converted into modern time units, 1 equals 14 minutes and 24 seconds. "Centimeter System" is the oldest and longest-used timing system in China. In the Han Dynasty, while using the "hundred engraving system", the method of "sun azimuth timing" was adopted, and the projection length of the sun was measured by a standard table to judge the time. The standard table consists of two parts: one is the benchmark or stone pillar for measuring the sun shadow standing upright on the flat ground, which is called the table; One is a rigid plate used to measure the length of the surface shadow in the direction of due south and due north, which is called Gui. Because the shadow of the sun can be measured by the unit of length, there is a saying that "an inch of time is an inch of gold". Every sun position measured by the standard gradually has a fixed name, which is the origin of time. During the Sui and Tang Dynasties, the "sun azimuth timing" officially evolved into "twelve o'clock timing". The combination of "hundred-engraving system" and "twelve-hour timing" made the timing system in ancient China tend to be perfect. In the late Ming and early Qing dynasties, western mechanical clocks were introduced to China, and the 24-hour clock system was also used. Because the decimal system can't be divisible in 12 hours, it is not easy to calculate, so it is changed to 96, 108, 120. It was not until the Qing Dynasty that a day and night was officially defined as 96 hours, 8 hours per hour, and further divided into upper and lower hours. In China's classical novels, there is often a saying that "the chop begins at 3: 00 noon". For example, The Journey to the West said in the ninth time: "It is said that the Prime Minister Wei Zhi is in the mansion, watching the dry elephants at night and enjoying the precious incense. He only heard the noise, but he was an angel from heaven. He held the jade emperor's golden jade seal together and watched him at three o'clock in the afternoon, dreaming of cutting the old dragon in the Jinghe River. " At 3: 30 noon, according to the current timing method, there are still 15 minutes before noon 12. Yin and Yang scholars think that the sun is at its peak at this time, while modern astronomy thinks that noon is at its peak. The two views are slightly different. At three o'clock noon, it is the time for the execution of ancient felons. At this time, the sun is the most abundant, and the yin will dissipate immediately after death. After being beheaded, the most heinous criminals "are not allowed to do ghosts" to show severe punishment. Those who commit misdemeanors can be executed at noon, giving them something to do. Therefore, "at three o'clock in the afternoon, I dreamed of cutting the old dragon in Jinghe" to show that the crime of the old dragon is extremely serious. Third, night shift: The personnel on duty in the Han Dynasty Palace were divided into five shifts, which were called "five shifts", so they were divided into five shifts at night, each with one hour. It is the first table of Xu Shi, the second table of Hai Shi, the third table of Zi Shi, the fourth table of Zhou Shi and the fifth table of Yin Shi. Their corresponding relationships are as follows: the first table date: Xu 19:00-2 1:00, and the second table date: Hai 21:00. 4. Point: In ancient times, [2] copper pot was used to measure time, and the following missing points were named. A shift is divided into five points, so the length of one point is equivalent to 24 minutes now. For example, The Journey to the West said for the ninth time: "Taizong woke up from his dream and never forgot. It's already five drums and three o'clock, and Taizong has set up a court to gather two classes of civil and military officials. " "Two o'clock at midnight" means midnight11:48; "Five drums and three o'clock" means 04: 12 in the morning.