Rules before results.

Year and month pillars follow solar terms. The year turns at Beginning of Spring; each month turns at its governing jie, at the calculated instant rather than at lunar month boundaries.

Every birthplace, including Guangdong, Hong Kong, Macau, and Taiwan, uses its historical civil-time offset and daylight-saving rule, birthplace longitude, and the equation of time to calculate apparent true solar time.

The current convention changes the day pillar at midnight. Late Zi remains on the same civil day. The user's entered time is applied exactly; proximity to a boundary is recorded but never blocks the result.

Ten Gods are derived from the Day Master; visible stems, hidden stems, combinations, clashes, harms, breaks, punishments, three-harmony frames, and seasonal assemblies are listed before interpretation.

The month branch and its main qi are the first structure reference. Exposure, rooting, support, restraint, and damage must be reviewed before a structure is confirmed.

Season, rooting, support, restraint, combinations, and transformations must be considered together. A numerical screen may organize evidence but cannot replace the classical judgement.

A stem combination or branch frame is only a candidate. Seasonal command, rooting, adjacency, obstruction, and the transformed qi must be checked before treating it as completed.

Cold, heat, dryness, and moisture are examined separately from ordinary balance. A climate candidate is not automatically the final favorable element.

Balance, climate, passage, and structure are evaluated separately, reconciled only after the chart structure is verified, and never converted directly into a product claim.

Direction follows year-stem yin/yang with sex; the start uses the solar-term interval convention in which three days correspond to one year. Boundary cases require cross-checking.