Methodology

How We Calculate

Every number on your chart comes from a published rule. Here is the whole pipeline, in order.

We do not guess, and we do not ask an AI to invent a chart. Your chart is computed by deterministic calendrical rules; AI is used only to interpret the finished result in plain language. Each step below is stated precisely enough that you or a practitioner can check it.

The pipeline

Birth data

We take birth date, birth time, birth location and gender. Location is required because it determines both the time zone and the longitude used for solar time correction.

True solar time correction

Clock time is not solar time. Two corrections are applied: a longitude correction, where one degree of longitude equals four minutes of time; and the equation of time, worth up to about sixteen minutes, caused by Earth's elliptical orbit and axial tilt. The corrected value is what feeds the hour pillar. The exact number of minutes applied to your chart is shown in the Chart Precision panel of your result.

Time zone and daylight saving

Your birth location is resolved against historical time zone data, including any daylight saving rules in force on that date. This matters more than people expect: mainland China observed daylight saving from 1986 to 1991, so a summer birth in that window sits one hour away from standard time.

Day boundary

Traditional practice starts the day at 23:00, the beginning of the Zi hour, not at midnight. We follow that convention, so a birth at 23:30 belongs to the following day's day pillar.

Calendar conversion

The Chinese calendar is lunisolar and inserts a leap month roughly every three years. Your birth date is converted with the standard lunisolar rules, handling leap months explicitly rather than approximating them.

The four pillars

The year pillar changes at the Beginning of Spring solar term, around 4 February, not at the lunar new year. The month pillar changes at each of the twenty-four solar terms, not on the first of the month. Day and hour pillars follow their own sixty-term cycles. These boundaries are the most common source of disagreement between calculators.

Five element count

Each heavenly stem counts as one. Earthly branches are counted through their hidden stems: the primary hidden stem counts as one, and the remaining hidden stems count as a half each. This is why your element chart shows half values — they are not rounding artefacts.

Ten-year cycles and annual pillars

The ten-year cycles are derived from the month pillar, with direction set by gender and the polarity of the year stem. The starting age is computed from the distance to the nearest solar term. Annual pillars follow the same sixty-term cycle and begin at the Beginning of Spring solar term.

Favorable elements

We use the support-and-restrain method, the most widely used and most explainable approach: we assess whether your day master is strong or weak given the month of birth, then identify which elements support it and which place pressure on it. Schools differ on the weighting, so we state our method plainly rather than implying there is only one answer.

Zi Wei Dou Shu

The Purple Star chart is produced by an established open-source engine from the same birth data, yielding the twelve palaces, the major and minor stars, the four transformations and the ten-year limits.

Feng Shui assessment

Facing direction is evaluated against your day master through the five-element generation and control relationships, which are directional by nature: wood generates fire, fire generates earth, never the reverse. Where the relationship is control rather than support, we say so plainly.

Where AI is used — and where it is not

AI never computes your chart. It receives the finished, structured result and writes the interpretation. It cannot invent a calculation and it cannot alter a chart. That is why identical birth data always yields an identical chart, while the wording of the interpretation may vary between generations.

Why we publish this

Most reading sites ask you to trust the result. We would rather show the method, so that anyone — a beginner or a practitioner — can judge whether it holds up. If a figure on your chart looks wrong to you, this page tells you exactly which step produced it.

This is a self-growth and reflection tool. It is not fortune-telling, and not medical, financial or legal advice.