Soon after, I found another thread.
Western astrology, in ancient times, was not originally used for fortune-telling. Its earliest function was identical to that of the Chinese solar terms: guiding agricultural production.
Ancient Mesopotamian farmers observed the stars to determine when to sow and when to harvest. Chinese farmers followed the solar terms to till and cultivate. At their core, both are the same thing: using celestial patterns to track the seasons — to track the rhythm of light and temperature across the year.
A Hypothesis
This led me to a hypothesis.
The two systems share nearly identical boundary dates. This means the seasonal rhythms they captured are consistent. And seasonal rhythms are, in essence, climate rhythms.
So: could the climate rhythms of ancient Mesopotamia and the Yellow River basin of China have been strikingly similar — thousands of years ago?
If the answer is yes, it would explain why two independently developed systems arrived at the same boundary dates for the same seasonal divisions.
Initial Verification
The initial evidence supports this hypothesis.
Both regions lie within the temperate zone between approximately 30°N and 40°N latitude. Both experience continental climates with four distinct seasons. The annual curves of light and temperature change with high similarity. While the specific values differ, the critical turning points — the peaks and troughs of heat, the inflection points of light — fall on nearly the same dates.
This is not coincidence. It is the same imprint left by the Sun’s path on two civilizations within the same latitudinal band.