Sources and limits
Know the
reference points.
Places: GeoNames
The offline place directory is built from GeoNames city, country and administrative-region data, with WGS84 coordinates and civil timezone identifiers. Data is credited to GeoNames, licensed under Creative Commons Attribution 4.0. Our directory filters the source to the US, Canada, UK, EU and EFTA, limits aliases and supplies country and region labels; those are adaptations, not an endorsement by GeoNames.
See the GeoNames data documentation. Place data can contain mistakes or historical exceptions. Select and confirm the exact place and its civil timezone; the tool will not replace your birthplace with a nearby city.
Civil time: IANA and tzdata
Historical civil-time rules come from the IANA Time Zone Database, supplied by the pinned Python tzdata package. The timezone-reference option uses the database's zone1970 table, country associations and reference-place labels. These reference points are not the visitor's birth coordinates and are used only with local civil time.
The IANA database is public-domain data; the Python package includes its upstream licenses. See IANA's license and the tzdata package license. Directory and timezone digests returned by the service identify the snapshot used; the deployment's private source manifest records source URLs, retrieval dates, versions, hashes, filtering and exclusions.
Calculation convention
The Gregorian date, recorded local civil time and confirmed context are passed to the existing deterministic engine using lunar_python version 1.4.8. The result is the element of the day stem, known as the Day Master in BaZi. This service uses a midnight day boundary and does not apply solar-time correction.
Different BaZi schools can use different day boundaries. For 23:00–23:59 we also display the late-Zi school difference. A date near midnight or an uncertain record needs care. Published day-calendar checks validate a limited calendar projection; they do not validate personality claims, every historical birthplace or professional paid readings.
The five symbols
The five phases — Wood, Fire, Earth, Metal and Water — come from Chinese thought. The Builder, The Spark, The Anchor, The Refiner and The Explorer are original Element & Self reflection prompts. They are not traditional personality classifications, a diagnosis or a prediction. Read the cultural overview at the Internet Encyclopedia of Philosophy.