Calculated first. Interpreted second.

A small, inspectable set of facts.

Birth Pattern Beta accepts a Gregorian date, a local civil time when known, a birthplace label, and an IANA time zone. The selected zone supplies the historical clock and daylight-saving rules used for the calculation.

• Gregorian birth date and recorded civil clock time
• An IANA birthplace time zone, including its daylight-saving rules
• Year, month, and day pillars
• An hour pillar when a reliable birth time is available
• Day Master element and polarity
• Visible occurrences of the five elements in the included stems and branches

A visible composition, not a complete chart.

YAO shows the stems and branches that the current engine can verify. Each included visible stem and branch contributes one occurrence to the element view. A known time normally gives eight visible symbols; an unknown time leaves the hour open and gives a smaller view.

The result is useful as a consistent lens. It is deliberately not presented as a full professional BaZi analysis.

Clock time stays visible in the policy.

Day and hour pillars use the recorded local civil clock with a midnight day boundary. Solar-term comparisons use a fixed UTC+08 reference because the calendar library expresses JieQi that way. Li Chun is the year boundary; other JieQi boundaries determine the month.

When a recorded moment is within 15 minutes of a solar-term boundary, the affected year or month pillar is left uncertain instead of being guessed. With an unknown birth time on a boundary day, YAO cannot choose between the possible pillars. A daylight-saving gap is rejected, and a repeated clock time stays uncertain unless the birth record identifies the occurrence.

Visible count means visible count.

“Wood 4 of 8” means four of the eight included visible symbols map to Wood. It is an occurrence count, not a weighted measure of strength, balance, health, ability, or personality. An absent element is not a deficiency, and a higher count does not replace the Day Master reference.

The same facts, given more room.

Personal Reading validates the calculated snapshot, applies authored interpretation rules, and presents eight structured chapters. Every interpretation block keeps a rule ID and the fact keys it uses. The report is deterministic for the same verified Birth Pattern, with no runtime AI-generated chart.

Each report records a light version trace: YAO Birth Pattern Beta and Reading Rules v0.2.1. A saved HTML report keeps those versions in its metadata so an older reading can be understood later.

Boundaries are part of the method.

• True solar time or longitude correction
• Hidden stems, Ten Gods, branch interactions, or seasonal weighting
• Day Master strength, Useful God, or favorable-element judgement
• Luck Pillars, annual timing, compatibility scores, or event forecasts

YAO is a cultural and interpretive practice for reflection. It does not establish medical, financial, legal, or personal outcomes. Your experience and informed decisions remain the final context.