Enjoy the morning and the moon, enjoy the summer.

Appreciate the moon and sunset, poetry and wine ride the years.

In the ancient calendar of China, there were four times, eight festivals, December orders, twenty-four solar terms and seventy-two periods about time. Twenty-four solar terms in 20 17 were listed in the world intangible cultural heritage list by UNESCO.

Although the frequency of seventy-two symptoms is not high, it is becoming more and more familiar to the public.

According to Mr. Song Yingjie, the seventy-two periods are the extension and refinement of the twenty-four solar terms, which are formed by the ancient people's long-term observation, combing, induction and summary of biological phenology (plants, birds, insects and animals) and abiotic phenology (weather phenomena).

Waiting takes five days as a unit, including the first vibration, first song, mating and migration of animals, germination, flowering and fruiting of plants, natural freezing and thawing, etc. Can be used as a time reference. For example, the spring shock is "the peach blossoms are in early bloom" and the mountain peaches are in full bloom.

Gorgeous spring has begun; In summer, the second day of the summer solstice is "cicadas begin to sing", birds are noisy and cicadas are singing, which is for the hot summer; The cold dew in autumn is "chrysanthemums have yellow flowers", chrysanthemums are in full bloom and autumn is strong; In winter, when beginning of winter is waiting for "the water begins to freeze", the water surface begins to condense into ice, and it gradually enters the dead of winter.