How to Calculate Bazi Luck Pillars
Calculate a Bazi Luck-Pillar sequence from the verified month pillar, direction rule, sexagenary order, solar-term interval, and exact start date.
Overview
A reproducible Luck-Pillar calculation has two outputs: the ordered stem-branch sequence and the date on which the first period begins. Verify the natal month pillar, determine forward or reverse movement under one declared convention, step through the sixty-Jiazi order, and then convert the relevant birth-to-solar-term interval into a start age. Do not round away the calendar inputs or silently change conventions.
At a glance
- Input 1
- Verified month pillar
- Input 2
- Direction convention
- Input 3
- Birth time and place
- Input 4
- Applicable solar term
- Outputs
- Sequence and start date
- Validation
- Library and frozen-report parity
Freeze the calendar inputs first
Confirm the civil birth time, time zone, calendar conversion, solar-term month, and resulting month pillar before calculating Luck Pillars.
If birth time or location is uncertain, retain that uncertainty because it can change the interval to a solar term or, near a boundary, the month pillar itself.
- Use one verified natal chart input.
- Preserve time-zone and solar-term provenance.
Step from the month pillar in the chosen direction
For a forward sequence, take the next valid Jiazi after the month pillar; for a reverse sequence, take the preceding one. Continue one stem and one branch at a time.
The natal month pillar is the anchor and is not normally repeated as the first Luck Pillar. Each later entry must remain a valid Yin-Yang stem-branch pair.
- Advance stems and branches together.
- Validate every generated Jiazi.
Calculate the first start date separately
Measure from birth toward the solar term required by the same direction convention, then convert the elapsed days and hours under the documented traditional ratio.
Production output should retain the precise start year, month, and day returned by the calculation library instead of exposing only a rounded age.
- Do not infer start age from the sequence.
- Store the exact start date and calculation version.
Validate before publishing interpretation
Compare direction, first pillar, start date, and successive period boundaries against deterministic fixtures and the calculation library used by the product.
A calculation update must not silently rewrite an already purchased or frozen report; versioned results need a visible methodology note.
- Test both directions and boundary births.
- Protect frozen historical outputs.
Sources and editorial basis
- 《三命通會》 (Sanming Tonghui)《三命通會》卷二「論大運」：陽男陰女由生後未來節氣順行，陰男陽女取生前節氣逆行，另列三日為年換算A historical compilation covering stems and branches, Ten Gods, Nayin, Shen Sha, and multiple classical pattern systems.
- 《淵海子平》 (Yuanhai Ziping)《淵海子平》行運諸論：以月柱及順逆次序推大運干支，再將各運與原局旺衰喜忌合看A foundational Ziping reference for branch months, hidden stems, roots, and stem-branch relationships.
- OpenFate Editorial Methodology大運計算頁對齊 calculateDaYun 的 direction、startYear、startMonth、startDay 與日期區間，保護凍結報告OpenFate separates deterministic chart calculation, traditional interpretation, and modern editorial explanation.