How to Calculate the Twelve Life Stages
Calculate a Twelve Life Stage by fixing the reference stem, its Changsheng branch, the direction convention, and the target branch before interpretation.
Overview
A reproducible Twelve Life Stage calculation needs four inputs: the reference Heavenly Stem, a sourced Changsheng starting branch, the adopted forward-or-reverse convention, and the target Earthly Branch. Count through the fixed twelve-name sequence from that anchor. Store the table version because some lineages differ on how Yin stems are traversed.
At a glance
- Input 1
- Reference Heavenly Stem
- Input 2
- Changsheng anchor branch
- Input 3
- Direction convention
- Input 4
- Target branch
- Output
- One of twelve stages
- Versioning
- Source table required
Freeze all inputs before counting
Select the stem whose qi phase is being examined, then identify the target branch and whether it belongs to the natal chart, a luck pillar, or an annual layer.
A result without those fields cannot be reproduced because changing either the reference stem or target branch changes the lookup.
- Never infer the stem from the target branch.
- Retain the timing layer with the result.
Use a sourced Changsheng anchor table
Each stem has a designated branch at which the Changsheng sequence begins. The remaining eleven stages follow from that anchor.
Rather than reconstructing the anchors from memory, production software should store a versioned ten-stem table and test every stem-branch combination.
- Cite the table or edition.
- Test all 120 stem-branch lookups.
Apply one declared direction convention
A common rule sends Yang stems forward through the branches and Yin stems in reverse. Some practical systems instead use a single forward table or assign Yin-stem phases differently.
The system should never switch conventions to obtain a preferred label; it should identify the adopted rule and preserve it in frozen reports.
- Version the direction rule.
- Do not blend incompatible tables.
Validate the lookup before interpretation
Check that twelve successive branch positions return the twelve labels exactly once and wrap to the starting branch without duplication.
Only after this parity check should the page discuss pillar placement, strength context, or timing. A correct lookup still does not make the label a literal event.
- Run cyclic completeness checks.
- Separate calculation certainty from interpretation.
Sources and editorial basis
- 《御定星曆考原》卷一《御定星曆考原》卷五十七「十二宮」十干長生所起與十二支順逆表：起點、方向與目標支共同決定結果A historical source for stem and branch Yin-Yang, Five Phase, direction, seasonal, and calendrical correspondences.
- 《三命通會》 (Sanming Tonghui)《三命通會》卷二五行寄生十二宮：列十干所臨十二位，計算須依固定干支次序A historical compilation covering stems and branches, Ten Gods, Nayin, Shen Sha, and multiple classical pattern systems.
- OpenFate Editorial Methodology十二長生計算頁使用版本化十干十二支對照表，驗證全部一百二十項並分開確定計算與後續解釋OpenFate separates deterministic chart calculation, traditional interpretation, and modern editorial explanation.