The 24 Seasonal Periods

二十四時期 The 24 Periods of The Chinese (Seasonal) Calendar

By the Spring and Autum Period in China (770–476 BCE), two major solar terms were established,日南至 ri nan zhi  (marking the sun at the most southern location) and日北至 ri bei zhi (marking the sun at the most northern location).  By the end of the Warring States Period (475–221 BCE), eight key solar terms were established: (Start of Spring, Vernal Equinox, Start of Summer, Summer Solstice, Start of Autumn, Autumnal Equinox, Start of Winter and Winter Solstice). These markings of the four seasons which we still follow today mapped changing positions of the sun and changes in natural phenomenal. The remaining solar terms to make up 24 ‘seasons’ in one calendar year were initiated in the Western Han Dynasty (206 BC–24 CE).