What is the Heavy Snow？
In the outer reaches of the Yellow River, the ancient Chinese used the phenology calendar, in which five days formed a hou, and three hous formed a solar term. A year was divided into 24 solar terms and 72 hous. Every hou corresponded to a natural phenomenon to explain the change of weather and phonological phenomenon. The hou could be divided into two categories: one was about biological phenomena, animals and plants. The other was about non-living things, such as water or thunder. The phenomena used to characterize the hous depended on the observations of the ancient people, so some of them we today know are false, such as the eagle turning into a turtledove, or the wild bird changing into a clam. In ancient times, however, they played an important role in guiding agricultural activities.
Major Snow is divided into three hous. In the first hou, the hoot of the hanhao bird is heard. In the eyes of the ancient Chinese, the hanhao bird was an animal of yin. Major Snow is the period when the yin reaches its peak and begins to decline, while the yang begins to grow. The hanhao bird feels the yang and stops hooting. In the second hou, as the yang grows, tigers, which are yang animals, start breeding. In the third hou of Major Snow, the liting, a kind of orchid, begins to sprout.
Key: Y refers to the last two digits of a year, such as 10 in 2010, 08 in 2008, D = 0.2422, L = the number of leap years, 21st century C = 7.18, 20th century C = 7.9.
Example: The date of Major Snow in 2088 = [88 × 0.2422 +7.18] - [88 / 4] = 28-22 = 6, so Major Snow starts on December 6.
Exceptions: For 1954, add one to the calculated result.