# Quizzman BaZi (Bát Tự / Tứ Trụ) — About

- HTML: https://lab.quizzman.com/tool/about-bazi
- Tool: https://lab.quizzman.com/tool/bazi-reading
- Canonical language: Vietnamese (`lang=vi`)

## Definition

**Quizzman BaZi** is a Four Pillars (Tử Bình / Tứ Trụ) calculator at lab.quizzman.com. It builds eight Can Chi characters for year/month/day/hour from the **Quizzman Calendar** astronomical core (UTC+7), then analyzes Ten Gods (Thập Thần), Hidden Stems (Tàng Can), Five Elements scoring, ten-year Luck Cycles (Đại Vận), and 26 Shen Sha.

Classical references: Uyên Hải Tử Bình, Tam Mệnh Thông Hội, Đích Thiên Tủy.

## Functions

1. Four Pillars from UTC+7 calendar (Lập Xuân year, solar-term month, Julian Day day, Daoist hour formula)
2. Ten Gods analysis (100 Nhật Chủ × Can mappings)
3. Five Elements strength + basic Useful God hints
4. Hidden stems with percent weights (e.g. Dần = Giáp 60% / Bính 30% / Mậu 10%)
5. Đại Vận forward/reverse by yin-yang + gender
6. 26 thần sát lookups
7. REST API

## Algorithms (core)

- **Year stem-branch:** starts at Lập Xuân (not Lunar New Year)
- **Month:** solar terms via VSOP87 sun longitude (shared Calendar core)
- **Day:** Julian Day Number
- **Hour:** classic Đạo Gia formula
- **Tàng Can:** fixed branch → hidden stem table with weights
- **Thập Thần:** relation of each stem to Day Master
- **Đại Vận:** direction from Day Master polarity + gender; start age from remaining solar term distance

## Accuracy meaning

Internal regression **128/128 PASSED** (Feb 2026): pillars, Ten Gods, Tàng Can (12 branches), Đại Vận, Shen Sha. Pillars inherit Calendar accuracy (108/108 + 19/19 edge). Does **not** claim destiny/fortune correctness — formulas are transparent for audit.

## FAQ

1. **How accurate?** 128/128 computation tests; calendar UTC+7 shared with Tử Vi / I-Ching.
2. **What algorithms?** Lập Xuân year, solar-term month, JDN day, Daoist hour, weighted Tàng Can, Ten Gods, polar Đại Vận.
3. **Fortune telling?** No prophetic claim; calculation only.

## Related wiki

- https://wiki.quizzman.com/wiki/bat-tu-tu-binh-tu-tru-he-thong-tinh-toan-theo-kinh-dien-co
- https://wiki.quizzman.com/wiki/5-kinh-dien-bat-tu-tu-binh-uyen-hai-dich-thien-tuy
- https://wiki.quizzman.com/wiki/thuat-toan-tinh-can-chi-tang-can-bat-tu-lap-trinh
- https://wiki.quizzman.com/wiki/can-chi-he-thong-dem-60-chu-ky-3000-nam-lich-su
- https://wiki.quizzman.com/wiki/quizzman-calendar-engine
- https://wiki.quizzman.com/wiki/thuat-toan-vsop87-tinh-tiet-khi-hoang-kinh-mat-troi
- https://wiki.quizzman.com/wiki/quizzman-iching-lich-phap-thuat-toan-do-chinh-xac
- https://wiki.quizzman.com/wiki/gioi-thieu-cong-cu-quizzman-kinh-dich-lich-phap-tu-vi-bat-tu-jck-font

## Related Lab pages

- Calendar: https://lab.quizzman.com/tool/about-calendar
- Tử Vi: https://lab.quizzman.com/tool/about-tuvi
- I-Ching: https://lab.quizzman.com/tool/about-iching
- Lab llms.txt: https://lab.quizzman.com/llms.txt