What this page is

The short version of MingPath's method: what we calculate, which rules we follow, where each rule comes from, and where the calculation stops being a calculation and becomes an interpretation. If a reading on this site ever surprises you, this is the page that says how it was produced.

In one line

Charts are computed from the traditional Chinese calendar using the established lunar-javascript library, following the standard BaZi rules for the four pillars, the Ten Gods and the luck cycles. Interpretive text is drawn from the classical corpus and marked as interpretation.

Step 1 — Calendar conversion

A birth date recorded in the Gregorian calendar is converted to the traditional Chinese lunisolar calendar. Two boundary rules matter and are frequently got wrong elsewhere:

• The year begins at 立春, not 1 January and not Lunar New Year. 立春 falls between 3 and 5 February. A birth on 20 January belongs to the previous BaZi year. This is the single most common source of a "wrong" zodiac animal.
• The month is defined by solar terms, not calendar months. Each BaZi month begins at one of the twelve 节 solar terms, so the month pillar is tied to the sun's position rather than to the first of the month.

We do not approximate these boundaries. Conversions use the lunar-javascript library's astronomical tables, and the resulting pillars are derived by the standard rules rather than by lookup tables of birth years.

Step 2 — True solar time

BaZi is built on local solar time; clocks run on administrative time. A birth recorded in Beijing time in Urumqi is roughly two hours away from the local sun, and two hours can cross an hour-branch boundary and therefore change the hour pillar — and with it a fifth of the chart.

We correct for two things: the difference between the clock timezone's central meridian and the birth location's longitude, and the equation of time, the seasonal drift between mean and apparent solar time. Where the correction is small enough not to move the hour pillar, it changes nothing. Where it is large enough to move it, the reading states that the correction was applied and by how much, rather than silently rewriting the input.

Step 3 — Deriving the four pillars

• Year pillar — from the lunisolar year, bounded by 立春.
• Month pillar — from the solar term governing the birth month, with the year stem determining the month stem sequence.
• Day pillar — from the continuous sixty-term day count. This is arithmetic on an unbroken cycle, not an interpretation.
• Hour pillar — from the birth hour's two-hour Earthly Branch, with the day stem determining the hour stem sequence.

Each pillar contributes a Heavenly Stem 天干 and an Earthly Branch 地支. Eight characters in total — hence 八字, "eight characters".

Step 4 — The Ten Gods 十神

Every character in the chart is classified by its relationship to the Day Master: as Peer 比劫, Output 食伤, Wealth 财, Officer 官杀, or Resource 印, each in a Direct and Indirect form. These ten categories are the analytical backbone of the reading, and the framework they come from is consistent across the classical sources.

What varies by school is emphasis — which structures a given lineage treats as most significant. Where we make a judgement call of that kind, we say so in the text rather than presenting it as settled.

Step 5 — Luck cycles 大运 and annual layers 流年

The luck cycles are ten-year periods that shift the chart's element balance over a lifetime. Their direction (forward or reverse through the sixty-term sequence) depends on birth year polarity and gender, and they begin at an age computed from the distance between the birth date and the nearest solar term. The annual layer sits on top, one stem and branch per calendar year. Together they are the only time-dependent part of the system, and the reason the same chart reads differently in different decades.

Step 6 — Interpretation, and where it ends

Everything above is deterministic: the same input always produces the same chart. Everything below is not.

Interpretation means taking a computed structure and describing it in the tradition's own vocabulary. That vocabulary is rich, consistent and old, but it is not measurement. A chart with excess Fire and insufficient Water does not doom a person to burnout any more than a soil test dooms a garden. The tradition itself says so: the chart is a mirror, not a script, and classical commentators were explicit that a person's conduct is not determined by the pillars.

So we hold to three rules in interpretive text:

• Say what the structure is, in the tradition's terms.
• Say what the tradition claims follows from it, marked as the tradition's claim.
• Do not convert either into a prediction of a specific event, a medical claim, a financial recommendation or a statement about a third party.

What we deliberately do not do

• No event prediction. No dates for promotions, meetings, diagnoses or outcomes.
• No medical claims. The wellness material is presented as a cultural and historical framework, not as physiology or treatment.
• No financial advice. Wealth stars in a chart are a symbolic structure, not an investment thesis.
• No fabricated authority. We do not invent practitioners, lineages, testimonials or case histories.
• No hidden layering. Where a folk practice enters — lucky numbers, lucky directions — it is labelled as folk practice.

Your data

The entire calculation runs in your browser. Birth details are held in your own browser's local storage, and nothing about your chart is transmitted to us. There is no account, no server-side profile and no third-party analytics attached to chart data. Details are in the privacy policy.

Known limits

• The hour pillar is only as good as the birth time you provide. An unknown hour weakens hour-dependent sections, and those sections say so.
• The 立春 boundary is calculated for the birth year; for births within hours of the boundary, small table differences between sources can flip the year pillar. We flag rather than hide the ambiguity.
• Sun-sign-style summaries of BaZi — one paragraph per birth year — are not something this site produces, because they conflate eight characters into one.

Corrections

If you believe a calculation, a translation or a claim on this site is wrong, tell us through the contact page and include the birth details and the page. Corrections that hold up are fixed and noted. Accuracy about the tradition is the point of the site; a reader who catches an error is doing us a favour.

Frequently asked

Does MingPath predict the future? No. We state what the systems say and where the limits are. We do not invent predictions, testimonials or medical claims. Readings are reflective insights, not predictions of specific outcomes.

Is this reviewed? The rules implemented are the standard published ones, and the interpretive text stays as close to classical descriptions as we can manage in English. Where a reading depends on a school's preference rather than on a settled rule, the text says so.