Day-Stem vs. Year-Stem Fate Stars (日干與年干)
Separate Fate Stars referenced from the Day Stem from rules based on the Year Stem, with exact polarity, target, source, and pillar provenance.
Overview
Stem-anchored Shen Sha tables must specify whether the reference is the Day Stem or Year Stem. Because those stems can differ in phase and polarity, switching the anchor changes the lookup row and may create false markers. Calculation preserves the source stem, matching target, pillar position, and table edition; interpretation remains secondary.
At a glance
- Day anchor
- Day Master stem
- Year anchor
- Natal Year Stem
- Critical detail
- Exact stem identity and polarity
- Target scope
- Defined by the source table
- Error risk
- Swapped anchor produces false matches
- Boundary
- Stem anchor is not biography
Day-Stem rules begin from the Day Master
Use the exact heavenly stem at the top of the day pillar and select its row in the cited table.
Element alone is insufficient because yin and yang stems may map to different target branches.
- Retain stem identity and polarity.
- Do not collapse Jia and Yi into Wood.
Year-Stem rules require a separate pass
The Year Stem can anchor a different classical table and should not inherit the Day-Stem result.
Its pillar position does not automatically make every returned marker a claim about ancestors, parents, or public life.
- Run the Year-Stem table independently.
- Keep traditional domains nonliteral.
Record the complete evidence tuple
Store the table version, reference stem, returned target, target pillar, and natal or timing layer for every match.
If a source allows multiple target positions, show them rather than reducing the result to a marker badge.
- Make each match reproducible.
- Preserve target placement.
Do not confuse lookup with Ten-God meaning
The same stem also participates in Five-Phase and Ten-God relationships, but those are separate calculations.
Cross-read them only after both facts are correct and never use one system to manufacture the other.
- Keep rule systems independent.
- Merge only at the evidence narrative.
Sources and editorial basis
- 《御定星曆考原》卷一《御定星曆考原》十干陰陽與神煞取法：同五行之陰陽干不可互換查列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》卷三天乙、文昌、祿等逐干取支條目：須保留所取天干與命中支A historical compilation covering stems and branches, Ten Gods, Nayin, Shen Sha, and multiple classical pattern systems.
- OpenFate Editorial Methodology日干與年干神煞頁分開兩種天干基準，保存陰陽、目標與柱位，且不與十神計算互相製造OpenFate separates deterministic chart calculation, traditional interpretation, and modern editorial explanation.