Origin of the Order of the 12 Chinese Zodiac Animal Signs 十二生肖排序的来历

十二生肖的选用与排列，是根据动物每天的活动时间确定的。
The selecion and order of the 12 Chinese Zodiac animal signs were determined according to animals’ time of activity.
十二生肖首先出现于计时。现在我们将一昼夜用二十四小时计时，古代天文学家将昼夜分为十二时辰，即：子、丑、寅、卯、辰、巳、午、未、申、酉、戌、亥。同时他们在观天象时，依照十二种动物的生活习惯和活动的时辰，确定了与时辰相对应的十二生肖。
The Chinese Zodiac initially originated from the division of time. Nowadays, we divide a day and night into 24 hours, however, ancient astronomers divided it into 12 shichen which is a two-hour period, namely, zi, chou, yin, mao, chen, si, wu, wei, shen, you, xu and hai. In astronomical observations, they chose 12 animal signs corresponding to each shichen according to animals’ living habits and their time of activity.
夜间十一点至次日凌晨一点，属子时，正是老鼠趁夜深人静，频繁活动之时，故称“子鼠”。
From 11 p.m. to 1 a.m. of the next day, it is zi. It is the time for rats to run around while people fall asleep, so we have the zi rat.
凌晨一点至三点，属丑时。牛习惯夜间吃草，农家常在深夜起来挑灯喂牛，故称“丑牛”。
From 1 a.m. to 3 a.m., it is chou. Oxen are used to eating grass at night, and farmers often get up late at night and feed them, so we have chou ox.
凌晨三点至五点，属寅时。此时昼伏夜行的老虎最凶猛，古人常会在此时听到虎啸声，故称“寅虎”。
From 3 a.m. to 5 a.m., it is yin. Because the tiger often moves about at night and ancient people often heard them roaring at this time, we call it yin tiger.
清晨五点至七点，属卯时。天刚亮，兔子出窝，喜欢吃带有晨露的青草，故为“卯兔”。
From 5 a.m. to 7 a.m., it is mao. Hares go out and eat green grass with morning dew during this period of time, so we call it mao hare.
早晨七点至九点，属辰时。此时一般容易起雾，传说龙喜腾云驾雾，又值旭日东升，蒸蒸日上，故称“辰龙”。
From 7 a.m. to 9 a.m., it is chen. It often mists at this time and legend says that dragons like to ride on clouds and mist. It’s also the time for the sun to rise, so we have chen dragon.
上午九点至十一时，属巳时。大雾散去，艳阳高照，蛇类出洞觅食，故作“巳蛇”。
From 9 a.m. to 11 a.m., it is si. The mist has vanished and the sun has risen up in the sky. Snakes go out to find food, so we call it si snake.
中午十一点至一点，属午时。古时野马未被人类驯服，每当午时，四处奔跑嘶鸣，故称“午马”。
From 11 a.m. to 1 p.m., it is wu. Before wild horses were domesticated in the ancient time, they usually ran around and neighed at this time. That’s why we call it wu horse.
午后一点至三点，属未时。有的地方管此时为“羊出坡”，意思是放羊的好时候，故称“未羊”。
From 1 p.m. to 3 p.m., it is wei. In some places, people call this period “sheep on the slope” because it’s good time for herding sheep. That’s why we call it wei sheep.
下午三点至五点，属申时。太阳偏西了，猴子喜在此时啼叫，故为“申猴”。
From 3 p.m. to 5 p.m., it is shen. The sun has moved to the western half of the sky. Monkeys love to screech at this time, so we call it shen monkey.
下午五点至七点，属酉时。太阳落山了，鸡在窝前打转，故称“酉鸡”。
From 5 p.m. to 7 p.m., it is you. The sun has set. Roosters went back to their nest, so we call it you rooster.
傍晚七点至九点，属戌时。人劳碌一天，闩门准备休息了。狗卧门前守护，一有动静，就汪汪大叫，故为“戌狗”。
From 7 p.m. to 9 p.m., it is xu. After a busy day, people closed their gates and went to sleep. Dogs guard the gates and bark in case of any noise, so we call it xu dog.
夜间九点至十一点，属亥时。夜深人静，能听见猪拱槽的声音，于是称作“亥猪”。
From 9 p.m. to 11 p.m., it is hai. In the still of night, people hear pigs digging troughs with their snouts, so we call it hai pig.
就这样，一天的时辰和动物搭配就排列了下来：子鼠、丑牛、寅虎、卯兔、辰龙、巳蛇、午马、未羊、申猴、酉鸡、戌狗、亥猪。后来人们把这种计时法用于纪年，就出现了十二生肖。
In this way, the 12 shichen and animal signs are matched and sequenced: zi rat, chou ox, yin tiger, mao hare, chen dragon, si snake, wu horse, wei sheep, shen monkey, you rooster, xu dog and hai pig. Later, people used this method of time labeling in numbering years and thus we developed the Chinese Zodiac.