The ninth chapter of the Yellow Emperor’s Classic of Internal Medicine, “Six Sections of Tibetan Imagery”
“The Yellow Emperor’s Classic of Internal Medicine: Six Sections of Tibetan Immortals, Chapter 9” (excerpt)
< strong>The five days are called the seasons, the three seasons are called the qi, the six seasons are called the time, and the four seasons are called the years, and each of them is governed by its main.
Translation: Five days are called one season; three seasons are called a solar term; six solar terms are called one time; four seasons called a year. In the four seasons of the year, each has its own vigor.