Birthplace and Bazi Calculation
Learn which birthplace data Bazi calculation needs, how it resolves historical time and longitude, and when location precision can change a pillar.
Overview
Birthplace matters to Bazi calculation because it identifies the historical civil-time rules and the longitude used by a selected solar-time method. The useful input is an unambiguous place with country or region, coordinates and an IANA time-zone identifier—not a symbolic judgment about the city. City-level coordinates are normally adequate away from a boundary; near an Hour-Branch or day boundary, the system should disclose coordinate and clock uncertainty.
At a glance
- Place identity
- City plus country or region
- Civil-time field
- Historical IANA time zone
- Solar-time field
- Longitude coordinate
- Usually sufficient
- Verified city-level coordinates
- Higher-risk case
- A corrected time near an hour or day boundary
- Privacy rule
- Do not require a street address
The place resolves clock rules and coordinates
A recorded local birth time cannot be mapped to UTC reliably without knowing where it occurred. The place selects the historical zone rule for that date.
If true solar time is enabled, the same place supplies longitude for the meridian correction. Latitude is not part of the basic longitude-time formula.
- Resolve both zone and longitude.
- Keep the original place label in provenance.
A city name must identify one real location
Many cities share names, and administrative borders or spellings can change. Country, region and coordinates let the system confirm the intended place.
A geocoder result should not silently jump to a better-known city. If several matches remain, the user needs to choose before chart calculation.
- Show the resolved place back to the user.
- Do not guess between same-name locations.
Required precision depends on boundary sensitivity
A small coordinate difference changes solar time by seconds or minutes and often leaves the same Hour Branch. Exact hospital coordinates are rarely necessary.
When the birth time sits near a branch or day boundary, compare a plausible coordinate range and recorded-time precision. Report multiple candidates if the boundary can be crossed.
- Use proportionate precision.
- Do not claim coordinate accuracy the source does not have.
Birthplace is not a label of personal quality
This calculation role does not mean a city, country, hemisphere or direction grants a better destiny. Feng Shui and relocation systems are separate topics with different inputs.
A street address creates unnecessary privacy risk for ordinary charting. Use the least precise location that safely resolves time zone and longitude.
- No geographic stereotyping.
- Minimize stored location data.
Sources and editorial basis
- IANA Time Zone DatabaseIANA 地區識別碼以具代表性的地點連結歷史民用時間規則，出生地必須先消除同名城市與國家歧義The maintained reference for historical local-time rules, UTC offsets, and daylight-saving transitions by location.
- U.S. Naval Observatory: The Equation of Time美國海軍天文台說明經度對地方太陽時的作用，支持出生地經度只作時間修正而非地理吉凶標籤An official astronomical explanation of apparent solar time, mean solar time, longitude offsets, and the equation of time.
- OpenFate Editorial Methodology產品只要求足以解析時區與經度的最小位置資料；邊界附近比較座標與記錄時刻誤差，不要求或保存不必要的街道地址OpenFate separates deterministic chart calculation, traditional interpretation, and modern editorial explanation.