The Yin Yang polarity is dynamic by nature and evolves continuously and cyclically.

Time does not stop. When the Yin principle becomes clearly dominant, it automatically triggers the opposite principle, and Yang reacts, growing in response to the dominance of Yin.

Let’s apply this paradigm to the annual cycle of the four seasons according to the ancient Chinese solar calendar. Around December 20, during the moment known as the Winter Solstice (in the northern hemisphere), the Yin principle is at its maximum expression. It corresponds to the shui phase (水, “Water”) of the cycle of the five “elements” (or five phases). It also corresponds to the peak of one of the four cosmic seasons of the year, in this case, dongtian 冬天, usually translated as “winter”, although it does not match completely to what is understood as “winter” in the Western world. In this shui phase, the Yin principle is clearly dominant, but it is not alone.

Although it is true that in the first 45 days until the Winter Solstice, the Yin principle still grows, one also has to understand that in the exact moment of the solstice (although the Yin principle continues to be dominant), is when the Yang begins to grow.

So that, from around February 4, the cycle enters a new phase, which includes 45 days until the Spring Equinox (which occurs around March 21, in the northern hemisphere) and the 45 days that follow the equinox, forming, in their entirety, the phase known as mu 木, as well as the season chuntian (春天, “spring”). And the cycle continues through its five phases, which are closely linked to the four seasons of the year.

This same paradigm can be applied to the daily cycle of the 24 hours of each day, corresponding to the 12 Chinese hours.