BaZi reference
Direct English definitions for the terms used in BaziRoute calculations, reports and educational guides.
Apply the terms to your chartReference
BaZi is a traditional Chinese system that represents a birth moment as four stem-and-branch pairs.
It is also called the Four Pillars of Destiny. BaziRoute calculates the chart structure first and treats interpretation as a separate layer.
Read related guide →Yin and yang describe paired polar qualities used throughout the stems, branches and Ten Gods.
They are relational categories rather than moral labels. Yang does not mean better or stronger, and yin does not mean passive or weaker.
The Five Elements are Wood, Fire, Earth, Metal and Water, understood through generation and control relationships.
The elements describe patterns of movement and relationship. Counting visible labels is not the same as evaluating chart strength or a favorable element.
Read related guide →Wood is the Five Element associated with growth, extension and connection.
Jia is yang Wood and Yi is yin Wood. Seasonal context and the rest of the chart modify the reading.
Read related guide →Fire is the Five Element associated with warmth, visibility and transformation.
Bing is yang Fire and Ding is yin Fire. Fire imagery does not guarantee confidence or extroversion.
Read related guide →Earth is the Five Element associated with centering, holding and cultivation.
Wu is yang Earth and Ji is yin Earth. Seasonal associations for Earth differ by interpretive tradition.
Read related guide →Metal is the Five Element associated with definition, boundaries and refinement.
Geng is yang Metal and Xin is yin Metal. Directness or precision is not evidence of a stronger chart.
Read related guide →Water is the Five Element associated with movement, depth and adaptation.
Ren is yang Water and Gui is yin Water. Movement in the imagery does not establish intuition or psychological traits.
Read related guide →Reference
The Four Pillars are the Year, Month, Day and Hour columns of a BaZi chart.
Each available pillar contains one Heavenly Stem and one Earthly Branch. A complete chart contains eight characters.
Read related guide →A Heavenly Stem is one of ten symbols formed by combining a Five Element with yin or yang polarity.
The ten stems are Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren and Gui. Every pillar has one stem above its branch.
Read related guide →An Earthly Branch is one of twelve symbols used below the Heavenly Stems in a BaZi pillar.
The twelve branches are commonly associated with zodiac animals, seasons, directions and hidden stems. A single animal is not a complete chart.
Read related guide →The Day Master is the Heavenly Stem of the Day Pillar.
It acts as the reference point for Ten God relationships and element comparisons. It is not a complete personality verdict.
Read related guide →Element presence is a count of visible element labels in the calculated chart.
BaziRoute keeps this count separate from strength, usefulness, balance and favorable-element judgments.
Read related guide →A six harmony is one of six fixed Earthly Branch pairs traditionally described as related.
BaziRoute names the structural pairing without assigning a good, bad or compatibility score.
Read related guide →A six clash is one of six fixed Earthly Branch pairs traditionally described as oppositional.
It is a structural relationship, not a prediction that a year, person or relationship will fail.
Read related guide →Reference
A solar term is an astronomical point based on the Sun reaching a specific apparent ecliptic longitude.
BaZi month boundaries generally use the twelve major terms called jie. Exact instants and time zones matter near a boundary.
Read related guide →Lichun is the solar term at 315 degrees of apparent solar longitude and the BaZi year boundary used by the current BaziRoute rule profile.
It is not always the same date as Lunar New Year. A birth between the two boundaries can expose the difference.
Read related guide →Jie are the twelve solar-term boundaries used to divide BaZi months.
The current engine changes the Month Pillar when the Sun crosses the relevant boundary, not simply at the start of a civil calendar month.
Read related guide →The day boundary is the rule determining when one BaZi day changes to the next.
The current profile changes the day at 23:00 local calculation time. Other schools may use midnight or different late-zi conventions.
Read related guide →True solar time adjusts civil clock time for longitude and the annual equation of time.
Some practitioners use it and others do not. BaziRoute exposes it as an explicit setting because it can change a pillar near a boundary.
Read related guide →An IANA time zone is a named geographic time-zone identifier such as Europe/London or Asia/Hong_Kong.
The identifier carries historical offset and daylight-saving rules. Results should record the time-zone data version used.
Read related guide →A rule profile is the named set of calculation and boundary choices used for a chart.
It can specify the year and month boundaries, day rollover, true-solar-time setting and interpretive mappings. Comparisons without the profile can be misleading.
Read related guide →Unknown birth time means the exact local clock time required for an Hour Pillar is unavailable.
BaziRoute produces a three-pillar chart, omits the Hour Pillar and shows alternatives around same-day year, month and day boundaries.
Read related guide →Reference
The Ten Gods are ten structural relationship categories between the Day Master and other stems.
They are not literal deities. Five relationship types appear in same-polarity and opposite-polarity forms.
Read related guide →Luck pillars, or Da Yun, are roughly ten-year periods that add changing stem-and-branch layers to the natal chart.
Starting age and direction depend on named rule choices. They are not included in BaziRoute’s current Foundation Report.
Read related guide →An annual pillar is the stem-and-branch pair associated with a particular BaZi year.
2027 is Ding Wei under the current cycle. A zodiac animal page is not a complete annual reading for an individual chart.
Read related guide →Interpretation is the meaning assigned to already-calculated chart structure within a named tradition.
It may include editorial guidance and AI language, but it must not alter the Four Pillars or invent uncalculated technical facts.
Read related guide →Reference
Structural analysis is the deterministic mapping of visible stems, branches and hidden stems to elements and Ten Gods.
It is chart structure, not a complete interpretation. BaziRoute currently labels this mapping `ten-gods-standard-mapping-v1`.
Read related guide →A chart snapshot is an immutable saved copy of a calculated chart and its rule/data versions.
Editing a birth profile creates a new snapshot rather than silently overwriting the historical result.
Read related guide →A prompt version identifies the instruction set used for an AI interpretation.
It is returned with AI results so later evaluation can distinguish output changes from model changes.
Read related guide →A response schema defines the required fields and structures in machine-readable AI output.
BaziRoute validates the response before showing it. Invalid structure is treated as an AI failure, not a successful reading.
Read related guide →Important boundary
BaZi schools differ in boundaries, hidden stems and interpretive emphasis. The definitions here describe BaziRoute’s current educational usage and named rule profile; they are not a claim that every practitioner uses every term identically.
Reviewed by BaziRoute editorial · Updated 27 October 2026 · For education and cultural reflection, not professional advice.