Method · v1.0.0
Calculation spec v1.0.0
The published rules behind every chart Mingfold computes.
Engine spec v1.0.0 · Owner: Marco Wade, Founder & Editor · Effective 8 November 2026.
Inputs
A birth date (Gregorian, or a Chinese lunar date converted with lunar_python 1.4.9 before any pillar rule runs), a wall-clock time, an IANA time zone and a longitude. A hand-entered place must supply a valid time zone and longitude; the engine fails closed rather than guessing.
Rules
- Historical civil time resolved from the IANA tz database, including daylight-saving transitions and ambiguous local times
- Apparent solar time correction from longitude and the equation of time
- Year pillar changes at 立春; month pillar changes at the 节 boundaries
- Day changes at 23:00 (late 子时 stem divergence documented)
- 五虎遁 for month stems, 五鼠遁 for hour stems, ten gods, hidden stems and na yin
Scope
v1.0.0 computes the four pillars, the day master, stem labels, hidden stems and na yin. It does not compute decade-scale luck cycles, yearly or monthly cycles, date selection, favourable elements, pattern labels or the traditional symbolic catalogue. Sex is not an input to the four pillars.
Verification
24 golden vectors, all passing; 12 can be independently cross-checked against lunar_python 1.4.9 and all agree. The spec, the tests and the chart schema are published together.
Full readable version: Method.