According to the way of numbering the years in Chinese lunar calendar, there are two seasonal division points in each month, making 24 in a year.

The seasonal division points are particular to China. In the long period of labor, ancient gradually realized the rule of climate change. According to the relationship between the sun and the earth, they divided all the days in a year into 2 parts to indicate the changes of seasons and climate. Thus, there is a seasonal division point about every 15 days; those in the first half of the year - from January to June, all fall around the 6th or 21th day of the month, and those in the later half of the year - from July to December, on about the 8th or 23rd day of the month.

The names and meanings of 24 seasonal division points are:

Beginning of Spring, Beginning of Summer, Beginning of Autumn and Beginning of Winter, which marks the starting point of four seasons. Vernal Equinox and Autumnal Equinox are the two points where the day and night are equal. Summer Solstice has the longest day and shortest night in a year, while the opposite is true for Winter Solstice. Rain Water means the start of the spring rains. Waking of Insects indecates that spring thunder awakens hibernating insects. Pure Brightness means the on set of spring when a bright and clean spring scene replaces the cold, withered and yellow scene of winter. Grain indicates that from that day, there will be more rainfall, which is beneficial to the growth of crops. Grain Budding shows that crops that will ripen in summer start to show plump seeds. Grain in Ear tells people that wheat has repened. Slight Heat and Great Heat indecate the full on set of summer, with Great Heat being the hottest day of the year. Limit of Heat shows that scorching summer days will soon be gone. White Dew tells people that dew appears in the morning to show that the weather is turning cold, and , as this intensifies, we move on to Cold Dew. Frost's Descent means the appearance of the first frost of the season. Slight Snow and Great Snow mean the arrival of the snowy season. Slight Cold and Great Cold indecate the degree of coldness in winter, with Great Cold being the coldest day of the season.

24 seasonal division points have great influence on farming of China. For convenience of menory, people compiles the Song for the 24 Seasonal Division Points.

"Following Beginning of Spring and Rain Water, Waking of Insect awaken Vernal Equinox. After Beginning of Summer, Grain Budding, Grain in Ear, and Summer Solstice, Slight Heat is connected with Great Heat. Beginning of Autumn and Limit of Heat is followed by White Dew, Autumnal Equinox, Cold Dew and Frost's Descent. And Beginning of Winter leads to Slight Snow, Great Snow, Winter Solstice, Slight Cold and Great Cold ..."