Methodology

How birth inputs become a chart—and where interpretation begins

Bazi Traces uses a deterministic calculation layer for the Four Pillars and related structured fields. AI-assisted features interpret that result; they do not create the chart from scratch.

This page describes the current implementation, including its limitations. It does not claim astronomical perfection, scientific validation, or expert verification.

Current pipeline

Five stages with distinct responsibilities

The same structured chart is carried forward from the calculator into the optional reading features.

Collect the birth context

The calculator requires a birth date, local civil birth time, birthplace, timezone, and gender selection.

City search uses city-timezones to suggest a place, coordinates, and an IANA timezone; users can also enter a city and choose a timezone manually.
Name and email are optional on the public calculator. They are not used to derive the Four Pillars.
If the exact birth time is unknown, the current interface substitutes 12:00 and marks the result with a warning.

Calculate the Four Pillars deterministically

The entered Gregorian date and local civil time are passed to lunar-typescript, which produces the calendar and Eight Characters data used by the product.

The calculation layer returns the year, month, day, and hour pillars, including their Heavenly Stems and Earthly Branches.
For the same accepted inputs and calculation version, this layer follows the same code path rather than asking a language model to guess the chart.

Build structured chart context

The result is enriched with fields that the interface and reading features can use consistently.

Current fields include the Day Master, zodiac, Na Yin, Ten Gods, hidden stems, and a Five Elements occurrence composition.
The Five Elements percentages count the four visible Heavenly Stems plus every hidden stem returned for the four Earthly Branches. Each occurrence counts once; branch surface elements are not counted separately, and the result is not a strength model.
Hidden stems come from lunar-typescript where available, with an internal branch mapping as a deterministic fallback.

Add timing context where available

The timing helper uses the same lunar-typescript Eight Characters object to request Da Yun and annual-cycle data.

For male or female selections, the library receives the corresponding traditional direction value and the product normalizes the returned 10-year cycles.
The current cycle is selected for the target year, and the annual Gan-Zhi is read from that cycle or from a deterministic calendar-year fallback.
For the current “other” gender selection, the product does not choose a traditional Da Yun direction and reports that the current luck cycle is unavailable.

Begin AI-assisted interpretation

Only after the structured chart exists can an optional AI reading, Full Report, or Guidance Chat response be generated.

The AI layer receives validated birth context, calculated chart fields, timing fields, and calculation warnings.
Its role is to synthesize symbolic themes and explain them in the requested language. It is instructed to use the supplied chart and not recalculate or replace its values.

Calculation versus interpretation

What is fixed by code and what remains interpretive

Deterministic output

Year, month, day, and hour pillars
Heavenly Stems and Earthly Branches
Day Master, zodiac, Na Yin, Ten Gods, and hidden stems
Five Elements occurrence composition
Da Yun and annual-cycle context when the library can provide it
Calculation and timing warnings

Generative interpretation

Plain-language summaries of symbolic chart patterns
Themes concerning temperament, learning, work, resources, relationships, and body rhythm
Longer Full Report synthesis and reflection prompts
Answers to chart-focused questions in Guidance Chat
Wording, emphasis, and synthesis that may vary between generations

AI does not calculate the Four Pillars from scratch. It interprets structured deterministic data produced by the calculation layer.

Current implementation

Libraries and helpers in use today

The main calendar and Eight Characters engine is lunar-typescript. The calculation helper creates a Solar value from the submitted Gregorian date and local civil time, reads the Lunar and EightChar objects, and derives the visible chart fields used across the product.

The timing helper uses lunar-typescript Yun, Da Yun, Liu Nian, Na Yin, and Ten Gods lookup data. City search uses city-timezones to suggest place and timezone context. These are implementation dependencies, not certifications or guarantees of interpretive accuracy.

The deterministic result is stored or passed as structured context for Free Reports, Full Reports, and Guidance Chat. Report pages keep a saved chart snapshot alongside the interpretation so users can see the calculation context used for that report.

Important limitations

What the current calculation does not correct or guarantee

Time handling is the most important technical boundary to understand before relying on the displayed chart.

Local civil time is used directly

The submitted date and clock time are used as entered. The selected timezone is retained as context, but the current Four Pillars calculation does not convert the input through that timezone.

True solar time is not applied

Longitude and birthplace coordinates are not used to shift the clock time for true solar time. The product does not claim true-solar-time correction.

Historical timezone and DST rules are not modeled

The current implementation does not reconstruct historical timezone offsets or daylight-saving transitions for the birth date. A correct IANA timezone selection does not remove this limitation.

Birth-time uncertainty affects the hour pillar

A small change near an hour boundary can change the hour pillar. When time is unknown, 12:00 is only a placeholder, so the hour pillar and time-sensitive interpretation should be treated as uncertain.

Timing data can be unavailable

Da Yun output depends on available library data and a supported traditional direction selection. The product surfaces warnings when a current cycle or annual row cannot be produced.

AI interpretation is variable

Generated content may differ between requests and may contain errors, omissions, awkward wording, or claims that do not fit the user’s actual circumstances.

Interpretive limits

Traditional and symbolic, not scientific prediction

Bazi is presented here as a traditional, symbolic interpretive system. Bazi Traces does not claim that its readings are scientifically validated, peer reviewed, or capable of establishing facts or predicting guaranteed events.

No chart, report, or chat response is medical, psychological, legal, financial, investment, tax, diagnostic, emergency, or other professional advice. Important decisions should use relevant evidence and qualified professional support.

Data boundary

Methodology explains categories, not user records

The public methodology describes the kinds of input and structured fields used. It does not expose anyone’s birth record, chart, report, chat history, email, payment reference, or private identifier. The Privacy Policy explains collection, service providers, retention goals, access, and deletion requests.

Read the Privacy Policy

Review the method, then inspect a real chart

The calculator shows the deterministic output and its warnings before you choose any optional AI interpretation.

Open the calculator Read the disclaimer