There were customs of “counting the nine-day periods” and “drawing the nine-day periods” among the ancient people. That is, people noted down the passage of the nine-day periods and the relevant weather changes with interesting pictures and poems. Sometimes, a painting of a plum tree with 81 blossoms was hung on the wall, and in the 81 days after the Winter Solstice, one blossom would be colored red each day. When all the plum blossoms were colored red, winter came to an end and spring arrived. This custom was prevalent among the educated class. For the common people, they would like to dram a picture with 81 circles, each representing a day, and recording the weather conditions of each day in the corresponding circle.

The method was as follows:
If it is cloudy, the upper half circle should be blackened;
If sunny, the lower half blackened;
If windy, the left half blackened;
If rainy, the right half blackened;
If snowy, a spot should be marked in the center;
After 81 circles are marked,
Spring wind brings burgeoning grasses and flowers.