Bazi Chart Calculation Order
Follow a reproducible Bazi chart calculation order from source validation and time resolution through Four Pillars and derived interpretation.
Overview
A reliable Bazi chart is built as a dependency chain, not as a collection of independent lookups. Validate the birth record and calendar first; resolve the birthplace, historical time zone and unique instant; apply a declared true-solar-time option and day-boundary policy; then determine the Year and Month Pillars from exact solar-term boundaries, the Day Pillar from continuous chronology, and the Hour Pillar from the effective local time and Day Stem. Only after the Four Pillars are stable should the system derive hidden stems, Ten Gods, interactions, strength, patterns, luck cycles and narrative interpretation. This order prevents a late input correction from leaving stale downstream results.
At a glance
- Step 1
- Validate the source record and calendar
- Step 2
- Resolve place, time zone and instant
- Step 3
- Apply declared time and boundary policies
- Step 4
- Calculate Year, Month, Day and Hour Pillars
- Step 5
- Derive relationships and timing layers
- Final requirement
- Keep a versioned audit trace
Validate source inputs before any symbolic calculation
Confirm the person, date, time, precision, birthplace, calendar type, leap-month status and source of the record. Reject impossible calendar dates and distinguish an unknown time from a convenient noon placeholder.
If the input is uncertain, represent the supported range now. It is safer to propagate explicit candidates than to attach false precision to every later layer.
- Keep original and normalized fields.
- Do not infer missing birth data from a desired result.
Resolve civil time to a unique instant and effective Bazi time
Use the birthplace and date to apply the historical IANA time-zone rule, including daylight-saving gaps or repeated times. Then apply true solar time only if the selected policy requires it and the longitude is available.
Next apply the declared 23:00 or midnight day boundary. These steps can change the effective date, hour branch or side of a solar-term boundary, so they must precede pillar calculation.
- Use policy fields rather than hidden defaults.
- Record every offset and correction separately.
Calculate the Four Pillars in dependency order
Determine the Year Pillar at Li Chun and the Month Branch at the current Jie interval; derive the Month Stem from the resolved Year Stem. Calculate the Day Pillar from a verified continuous day count under the selected boundary.
Finally select the Hour Branch from the effective clock interval and derive its stem from the Day Stem. This order makes the Five Tigers and Five Rats relationships testable invariants rather than decorative tables.
- Recompute dependent pillars after any upstream change.
- Validate adjacent boundary cases, not only midday examples.
Derive analysis only from the frozen pillar state
Hidden stems, Ten Gods, combinations, clashes, strength, structures, useful-god strategies, luck cycles and prose all depend on the Four Pillars and declared school policies. Generate them only after the canonical chart is stable.
Store engine version, policies, source fields, normalized times, solar-term distances and pillar outputs. A reproducible chart can be audited; a bare list of eight characters cannot explain why two systems differ.
- Separate deterministic calculation from interpretation.
- Invalidate downstream caches when an upstream input changes.
Sources and editorial basis
- IANA Time Zone DatabaseIANA 歷史時區先把出生地民用時間還原成唯一瞬間，包含日光節約時間的缺口與重複時段，必須先於節氣和四柱判定The maintained reference for historical local-time rules, UTC offsets, and daylight-saving transitions by location.
- Hong Kong Observatory: Heavenly Stems and Earthly Branches香港天文台的干支次序、月份與時辰對照支持先固定年、月、日柱，再按五虎遁與五鼠遁相依關係推導月干與時干An official modern reference for the canonical stem and branch orders, the sexagenary cycle, and calendrical use.
- OpenFate Editorial MethodologyOpenFate 計算器先校驗輸入與時間政策，再由公開 Bazi engine 產出四柱，最後才建立藏干、十神、作用、旺衰、格局與敘事層OpenFate separates deterministic chart calculation, traditional interpretation, and modern editorial explanation.