四柱 · Four Pillars
BaZi, often called Chinese astrology or the Four Pillars of Destiny, uses a traditional Chinese calendrical and interpretive system. The year, month, day, and hour each have a Heavenly Stem and an Earthly Branch. Together, they form the eight characters of a birth chart.
日主 · Day Master is the Heavenly Stem of the Day Pillar. Its yin or yang quality and phase provide a starting point for interpretation. It is not equivalent to a Sun sign or a validated personality type.
五行 · Five Phases
Wood 木, Fire 火, Earth 土, Metal 金, and Water 水 are often called the Five Elements. “Phases” emphasizes relationships and change rather than literal substances in your body.
生克 · Generating and Regulating Relationships describe traditional relationships among the phases. The Snapshot counts only the visible stem and branch phase assignments. It does not weight seasons or hidden stems, and these counts are not a measure of balance, health, or Day Master strength.
Calculation conventions
- Calendar: Gregorian birth dates from 1900 through today. We use the open-source 6tail lunar-typescript library, pinned to version 1.8.6.
- Place and time zone: enter the recorded local clock time and confirm a named IANA zone for your birthplace. Historical offset and daylight-saving rules come from the runtime’s time-zone database through Temporal. We do not guess the zone from your current location.
- Year and month: the Year Pillar changes at Li Chun; Month Pillars change at the relevant solar terms. We convert the birth instant to Asia/Shanghai before using the library’s Chinese-standard-time solar-term calculations.
- Day and hour: we use the birth location’s civil date and clock time. Day changes at midnight (library sect 2). The library advances the Hour stem at 23:00; this late-Zi-hour convention may differ from other practitioners.
- No solar-time correction: we do not adjust for longitude or the equation of time. Birthplace does not secretly apply a true-solar-time correction.
- Unknown or approximate time: we omit the Hour Pillar. We compare the start and end of the birth date for a Year or Month change and leave any affected pillar unresolved.
- Clock changes: exact or approximate local times that repeat or do not exist during a clock change are rejected. You can use an unknown-time profile instead. Historical records and time-zone databases may themselves be incomplete.
Method version: civil-time-1.0. These choices make the computation repeatable; they do not scientifically validate the interpretation.
Three different kinds of statement
| Layer | Example |
|---|---|
| Calculated chart value | The Day stem is 乙, Yin Wood, under the stated rules. |
| Traditional association | Yin Wood is associated with adaptive, relational growth. |
| Reflection prompt | Where do you bend too far to preserve harmony? |
A calendar value can be checked against calculation rules. An association is a traditional reading. A question invites your judgment; it is not evidence about your personality.
流年 · Annual Cycle
A traditional annual cycle offers symbolic themes to reflect on. It cannot establish the probability of an event, identify a safe investment, or determine a relationship’s future.
The free Snapshot does not calculate longer luck-cycle direction or starting age and does not need sex assigned at birth. If a future reading includes those calculations, it will explain the chosen convention and offer a core-profile-only alternative.
AI and review
Free Snapshots use fixed editorial text for each Day Master, attached to calculated chart data. No birth data is sent to an AI model. The complete report is a separate product in preparation; its AI assistance and named human review will be disclosed before purchase.