The calendar layer
The birth form takes a Gregorian date, local clock time and IANA time zone. Luxon resolves the historical offset, including daylight-saving rules. Invalid dates, nonexistent local times and repeated daylight-saving times are rejected instead of silently guessed.
The calendrical engine is lunar-typescript. For the solar-term year and month boundaries, the same birth instant is expressed in Asia/Shanghai, the reference used by its solar-term table. Day and hour are calculated using the entered place’s civil time.
The chosen convention
We use the library’s sect 2 convention: the day pillar changes at midnight, with the library’s documented late-Zi hour stem behavior. We do not apply a longitude correction or the equation of time. Other schools can legitimately produce a different day/hour result near boundaries.
A time zone is not a precise birth coordinate. We ask users to choose their birthplace’s time zone and show it in the result. We do not pretend to calculate true solar time from a city name.
The interpretive layer
The ten named archetypes are our editorial interpretations of the Day Master metaphors. The five-element bars count visible stem and branch categories. Neither layer is a validated psychological assessment.
A complete reading uses AI to expand the supplied chart into reflection themes and practical questions. It is instructed to avoid predictions, diagnoses, financial recommendations and claims that every association must fit.
What the research trial evaluates
The trial asks whether the experience is clear, useful, personally meaningful and worth paying for. It also asks what does not fit. It is product research, not a scientific study establishing that birth time predicts personality.
You can disagree with a result. Your feedback is not published as a testimonial, and access to the trial is not conditional on a positive rating.
Find the story in your own chart.
Calculate your four pillars, meet your Day Master and take away a signature card.
Reveal my signatureCalendar reference: Hong Kong Observatory: the 24 solar terms. Calculation engine: lunar calendar documentation. Archetype labels, exercises and artwork are modern editorial interpretations. Read our method.