References

Sources and further reading

Our articles separate calendar calculations, traditional terminology, and interpretation. The references below document the calendar, time-zone, location, and software inputs used by the site; they do not validate personal predictions.

Calendar and civil time

Hong Kong Observatory — Chinese calendar and solar-term reference. Used as a public reference when explaining calendar and solar-term boundaries.
IANA Time Zone Database. The calculator’s runtime uses IANA zone identifiers to look up historical civil-time and daylight-saving offsets.

Calculation and place data

lunar-typescript. The site uses this open-source calendrical library to derive Four Pillars and ten-year-cycle data from the adjusted birth time.
GeoNames. International city names and reference coordinates are derived from its cities5000 data under CC BY 4.0.
Ministry of Civil Affairs of the People’s Republic of China. Mainland-China administrative names are checked against its 2023 division-code material.

Traditional terminology

Heavenly Stems, Earthly Branches, Hidden Stems, the 60 Jiazi cycle, Five Elements, Day Master, Ten Gods, and Luck Pillars are presented as traditional cultural vocabulary. Schools do not use every boundary or interpretation rule in the same way. Each article therefore states its calculation scope and links to related checks rather than presenting one interpretation as universal.

How to verify a page

Use the article’s update date, compare its stated input and boundary assumptions with the methodology, and report a specific factual, translation, or calculation-method issue through the editorial policy. Last reviewed: September 1, 2026.