After this day, many places in China go through the coldest period, which is called in Chinese, “Shu Jiu”. 

从冬至以后，中国的绝大部分地区都会经历最寒冷的时期，中国人叫它”数九“。

In total, there are nine periods with nine days for each. In the first and second nine days, people keep their hands in pockets; in the third and fourth nine days, people can walk on ice; in the fifth and sixth nice days, people can see willows along the river bank; in the seventh and eighth nine days, the swallow comes back and in the ninth nine days, the yak starts working.

这一共有九个时期，每个时期分别有九天。在”一九“和”二九“，手放口袋就能避寒；”三九“和”四九“，路上会结冰；”五九“和”六九“，可以看到河岸边柳树抽芽了；在”七九“和”八九“，燕子回归，在最后的”九九“，牛开始犁地。