Earthly Branches and Seasons (地支與季節)
Map Yin–Mao–Chen to spring and the remaining branch trios to summer, autumn, and winter while keeping solar terms separate from local weather.
Overview
Yin, Mao, and Chen correspond to spring; Si, Wu, and Wei to summer; Shen, You, and Xu to autumn; and Hai, Zi, and Chou to winter. These are solar-term and traditional seasonal coordinates used in month-command analysis. They do not report actual local temperature, rainfall, climate, or a person’s health.
At a glance
- Spring
- Yin, Mao, Chen
- Summer
- Si, Wu, Wei
- Autumn
- Shen, You, Xu
- Winter
- Hai, Zi, Chou
- Time basis
- Solar-term month boundaries
- Not equivalent
- Seasonal symbolism is not local weather or medical data
Use four ordered three-branch groups
Each season contains an opening, central, and closing branch in the traditional solar-month sequence.
The closing Earth branches—Chen, Wei, Xu, and Chou—mark transitions while retaining distinct hidden stems and relations.
- Keep the three positions in order.
- Do not merge the four Earth branches.
Month branch gives season its chart role
When a branch commands the birth month, its seasonal state becomes primary evidence in many strength and structure methods.
The same branch outside the month pillar still has a seasonal correspondence, but it does not become the month command.
- Identify the actual month pillar.
- Separate correspondence from command.
Boundary dates require astronomical resolution
Seasonal branch months change at defined solar terms, so a birth near a transition cannot be assigned safely from a date label alone.
Historical time zone, location, timestamp precision, and the selected ephemeris can affect which side of the boundary applies.
- Resolve the instant, not just the date.
- Display uncertainty near boundaries.
Traditional season is not climate or diagnosis
A summer branch does not prove heat exposure, inflammation, mood, fertility, or health, especially across hemispheres and climates.
Weather, medicine, agriculture, and safety decisions require direct local data and qualified expertise.
- Do not literalize seasonal imagery.
- Keep medical and climate claims out.
Sources and editorial basis
- 《禮記・月令》《禮記·月令》孟春至季冬：寅卯辰、巳午未、申酉戌、亥子丑的四時月序An early classical source for the seasonal grouping of Jia-Yi, Bing-Ding, Wu-Ji, Geng-Xin, and Ren-Gui.
- Hong Kong Observatory: The 24 Solar Terms香港天文台二十四節氣資料：節氣時刻界定傳統季節月令的轉換An official astronomical explanation of the 24 solar terms, their 15-degree divisions along the ecliptic, and the alternating major and minor terms.
- 《御定星曆考原》卷一《星曆考原》十二月建與四時：地支季節配屬、月令及季末四土的差異A historical source for stem and branch Yin-Yang, Five Phase, direction, seasonal, and calendrical correspondences.