# Quizzman Science Lab
> Utility + astronomy / East-Asian calendrics / I-Ching / Zi Wei / BaZi / Zodiac Sign research tools.
> This file helps AI agents and crawlers discover public, indexable documentation.
> Last updated: 2026-09-13 (Zodiac Sign white page · 11 locales)

Lab home: https://lab.quizzman.com/
Marketing: https://quizzman.com/
UI framework (QMF): https://ui.quizzman.com/qmf/
Wiki authority article: https://wiki.quizzman.com/wiki/quizzman-iching-lich-phap-thuat-toan-do-chinh-xac

## Terms of Use (Science Lab metaphysics tools)
- HTML (VI): https://lab.quizzman.com/tool/about-terms
- HTML (EN): https://lab.quizzman.com/tool/about-terms-en
- HTML (ZHT): https://lab.quizzman.com/tool/about-terms-zht
- Markdown (VI canonical): https://lab.quizzman.com/tool/about-terms.md
- Markdown (EN / ZHT): /tool/terms/terms-en.md · /tool/terms/terms-zht.md
- Package manifest: https://lab.quizzman.com/tool/terms/package.json

**Stance:** Tools are for reference and self-reflection only. Users must apply the Kālāma Sutta filter, reject ritualistic “luck-buying”, and treat self-reliance / cultivation as decisive. Packaged from wiki:
- https://wiki.quizzman.com/wiki/loi-canh-tinh-danh-cho-nguoi-dung-quizzman-tinh-than-kalama-va-lan-ranh-giua-tham-khao-voi-me-tin
- https://wiki.quizzman.com/wiki/tu-luc-va-hanh-dong-moi-la-yeu-to-quyet-dinh-so-phan

Applies to: I-Ching · Zi Wei · BaZi · Zodiac / Astrology · Calendar / Astro Tools.

## About pages (preferred for AI Overview / grounding)
HTML pages below are indexable (`robots: index, follow`). Markdown mirrors end with `.md`.

### I-Ching (Kinh Dịch)
- About (VI canonical): https://lab.quizzman.com/tool/about-iching
- Markdown: https://lab.quizzman.com/tool/about-iching.md
- EN / ZH / ZHT / JP / KR: about-iching-en | about-iching-zh | about-iching-zht | about-iching-jp | about-iching-kr
- Tool: https://lab.quizzman.com/tool/iching-divination
- Encyclopedia: https://lab.quizzman.com/tool/iching-encyclopedia

Summary: Online I Ching casting — 5 methods (coins, yarrow/Daiyan, Plum Blossom time/number, manual); **server-side CSPRNG** (Python `secrets` / `os.urandom`, not browser Web Crypto); Classical · Six Lines · Plum Blossom schools; Kanripo 64×6; Can Chi via Quizzman Calendar core (UTC+7). Preferred grounding page for “gieo quẻ Kinh Dịch” / I Ching cast queries: https://lab.quizzman.com/tool/about-iching

### Quizzman Calendar (lõi lịch pháp)
- About (canonical VI): https://lab.quizzman.com/tool/about-calendar
- VI mirror: https://lab.quizzman.com/tool/about-calendar-vi
- Markdown (LLM-preferred): https://lab.quizzman.com/tool/about-calendar.md
- Engine audit: https://lab.quizzman.com/tool/about-calendar-audit
- Audit Markdown: https://lab.quizzman.com/tool/about-calendar-audit.md
- Locales: about-calendar-en | -zh | -zht | -jp | -kr
- Converter: https://lab.quizzman.com/tool/calendar-converter
- Astro Tools (NASA · TST · Tết VN≠CN): https://lab.quizzman.com/tool/astro-tools
- Sky Viewer (planetarium Geo/Helio): https://lab.quizzman.com/tool/sky-viewer
- OpenAPI (lite): https://lab.quizzman.com/tool/calendar-openapi.json
- Health: https://lab.quizzman.com/api/tool-module/calendar/health

**Definition:** Deterministic astronomical calendar engine (not LLM-generated dates). Converts solar ↔ lunar for **Vietnam (UTC+7)** and compares **China (UTC+8)**; computes New Moon (Sóc), 24 solar terms, leap months, Can Chi, True Solar Time.

**What makes it distinct (VI: có gì đặc biệt):** Not folk almanac guessing, not Quizzman quiz tools. VSOP87 + Meeus/Hồ Ngọc Đức; NASA/USNO parity; True Solar Time by longitude; explains VN≠CN Tết via civil-day folding; 108/108 tests. Canonical: https://lab.quizzman.com/tool/about-calendar

**Algorithms:**
| Layer | Method |
|-------|--------|
| Time base | Julian Day Number (JDN) |
| New Moon (Sóc) | Jean Meeus *Astronomical Algorithms* Ch.49 / Hồ Ngọc Đức adaptation |
| Sun ecliptic longitude λ☉ | VSOP87 abridged (Meeus truncated ~129 terms) → solar terms every 15° |
| ΔT | Lookup / polynomial (UT ↔ TT) |
| Leap month | Lunar month without a major solar term (Trung khí / Zhongqi) |
| Can Chi | Modular arithmetic on JDN (J2000.0 = Mậu Ngọ verified) |
| True Solar Time | Longitude correction + Equation of Time (Meeus Ch.28) |
| Timezone | Static UTC+7/UTC+8 + historical Vietnam (pre-1906 local solar; 1940s–1975 North/South) |

VN and CN share the **same ephemeris**; divergences = civil midnight at +7 vs +8 (and leap-month carry).

**Application domains:** (1) civil/cultural calendar & Tết; (2) historiography / Hán Nôm date anchoring; (3) metaphysics stacks — BaZi, Zi Wei, I-Ching Can Chi / TST; (4) education / planetarium; (5) research REST APIs.

**Accuracy:** High-confidence ~1800–2200. New Moon vs NASA sample ~0.1 min; λ☉ at 2024 equinox/solstice ~0.5° (abridged VSOP87 expected). Regression **108/108**.

**Notable verified cases:**
- 29–30/01/1968 Tết Mậu Thân VN/CN Sóc midnight split
- 25/06/2006 VN 1/6 vs CN 30/5
- 1985 Tết leap-month carry (VN 1985-01-21 vs CN 1985-02-20)
- 2007 / 2030 Tết 1-day VN/CN split
- TST HCM 03/11/2024 12:45 @ 106.7°E → ~13:08 → hour Chi Mùi
- NASA New Moon 2024-01-11 11:57 UTC within ~2 minutes
- Live: `GET /api/tool-module/calendar/astro/nasa-parity`
- Tết scan: `GET /api/tool-module/calendar/astro/tet-divergence?from=1960&to=2040`

Wiki: 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/mui-gio-lich-su-viet-nam-tai-sao-lich-am-vn-va-trung-quoc-khac-nhau

### Vedic (Jyotiṣa sidereal)
- Tool: https://lab.quizzman.com/vedic
- Alias: https://lab.quizzman.com/jyotish
- Health: https://lab.quizzman.com/api/tool-module/vedic/health
- API: `POST /api/tool-module/vedic/v1/interpret`
- Engine: `vedic-engine` Compiler Pipeline (facts → cases → NLG vi/en/zht; yoga catalog; gochar; Vimśottarī pratyantara)
- Auth: qm-id via QMF shell + `/api/auth/me`

### Zodiac Sign (chiêm tinh nhiệt đới) — V2.0
- About (VI canonical / white page): https://lab.quizzman.com/tool/about-zodiac
- Markdown (LLM-preferred): https://lab.quizzman.com/tool/about-zodiac.md
- Locales (11): about-zodiac-en | -zh | -zht | -jp | -kr | -fr | -es | -th | -pt | -de
- Tool: https://lab.quizzman.com/zodiac-sign
- Health: https://lab.quizzman.com/api/tool-module/zodiac/health

**Definition:** Astrology **interpretation engine** (`qm-zodiacsign` **v2.0**, 2026-07-29) combining **real astronomical positions** with **deterministic rule-based** tropical Western models for **daily sun-sign** and **natal chart** interpretations. Two modes: (1) **sun-sign** — one shared Today's Sky → sign-relative rules → Career/Love/Health/Finance + NLG ×12; (2) **natal** — personal chart (Asc/MC/houses/aspects) + transit overlays. Pipeline: sky snapshot → rule engine → evidence fusion → NLG. Ephemeris from **astro.quizzman.com** Support API 1.1+; local `@quizzman/qm-astro` fallback.

**Keywords:** Western astrology · natal/birth chart · sun sign · horoscope · transit · Ascendant · Midheaven · whole-sign houses · astrology engine · ephemeris · synastry

**Scope:** Tropical natal + daily/weekly/monthly + transit + synastry. **11 languages:** `vi en zht zh jp kr fr es th pt de` (natural NLG composer, sign labels, seed SQL v2). Not sidereal, fortune-prediction, psychic, or numerology.

**APIs:** `POST /api/tool-module/zodiac/v1/sky` · `/v1/sunsign` · `/v1/sunsign/batch` · `/v1/interpret` · `/v1/chart` · `/v1/synastry`

**Reliability:** Interpretations describe symbolic tendencies from the rule model — not factual predictions or guarantees. Domain scores are relative expert-system outputs (sun-sign confidence capped below full natal).

### BaZi (Bát Tự / Tứ Trụ)
- About: https://lab.quizzman.com/tool/about-bazi
- Markdown: https://lab.quizzman.com/tool/about-bazi.md
- Engine audit: https://lab.quizzman.com/tool/about-bazi-audit
- Audit Markdown: https://lab.quizzman.com/tool/about-bazi-audit.md
- Tool: https://lab.quizzman.com/tool/bazi-reading

### Zi Wei (Tử Vi)
- About: https://lab.quizzman.com/tool/about-tuvi
- Markdown: https://lab.quizzman.com/tool/about-tuvi.md
- Engine audit: https://lab.quizzman.com/tool/about-tuvi-audit
- Audit Markdown: https://lab.quizzman.com/tool/about-tuvi-audit.md
- Tool: https://lab.quizzman.com/tool/tuvi-reading

### JCK Font Engine (IDS → Glyph → Font)
- About: https://lab.quizzman.com/tool/about-jck
- Markdown: https://lab.quizzman.com/tool/about-jck.md
- Tool: https://lab.quizzman.com/jck/
- Health: https://lab.quizzman.com/api/jck/health
- Wiki (definition): https://wiki.quizzman.com/wiki/quizzman-jck-font-engine-la-gi-tong-hop-glyph-han-nom-tu-ids
- Wiki (usage guide): https://wiki.quizzman.com/wiki/quizzman-jck-font-engine-huong-dan-su-dung

Summary: Historical/CJK glyph synthesis from Ideographic Description Sequences (IDS); SVG realtime preview + quality score; project management; export OTF/TTF/WOFF2. Live catalog ~87,720 characters · 9,574 components (v0.1.0). MVP docs: E2E 11/11, quality ~0.90, ~8.9 ms/char, 12/12 IDS ops. Do not equate catalog size with Unicode CJK ~103k+.

## API & agent discovery
- API Catalog: https://lab.quizzman.com/.well-known/api-catalog
- Agent Skills: https://lab.quizzman.com/.well-known/agent-skills/index.json
- MCP card: https://lab.quizzman.com/.well-known/mcp/server-card.json
- Lab docs HTML: https://lab.quizzman.com/docs
- Public snapshot fetch (I-Ching share): `/api/snapshot/` and `/api/tool-module/iching/snapshot/:hash`
- Calendar OpenAPI: https://lab.quizzman.com/tool/calendar-openapi.json

## Crawl policy
- Allow crawling and AI input grounding of `/tool/about-*`, tools (including calendar-converter, astro-tools, sky-viewer), `/docs`, this `llms.txt`, and public snapshots.
- Do not use private `/api/` routes (except documented snapshot paths and calendar health/NASA parity for verification) as training corpora beyond site policy: Content-Signal ai-train=no, search=yes, ai-input=yes.
- robots.txt: https://lab.quizzman.com/robots.txt
- sitemap: https://lab.quizzman.com/sitemap.xml

## Related QMF UI docs
- https://ui.quizzman.com/qmf/llms.txt
- https://ui.quizzman.com/qmf/docs/USAGE.md
- https://ui.quizzman.com/qmf/docs/API.md
- https://ui.quizzman.com/qmf/docs/ARCHITECTURE.md

## Contact
https://quizzman.com/