1 Scope
The scope covers core astronomical mechanics (VSOP87 abridged, Meeus Chapter 49 New Moon, Delta T interpolations), civil day boundaries, Twelve Officers, Twenty-Eight Mansions, and historical Vietnamese timezones.
2 Audited artifact
@quizzman/qm-calendar v1.2.0 (commit 6e8b4f1). NPM package and canonical compiled TypeScript distribution.
3 Environment
Node.js 20.17.0 LTS on Linux x86_64 (glibc 2.36), IEEE 754 double precision floating-point arithmetic.
4 Method
Deterministic symbolic verification, automated differential testing against USNO 2024 Astronomical Almanac and NASA Five Millennium Catalog of Solar Eclipses, and exhaustive roundtrip spanning 146,462 consecutive days (1800–2200).
5 Reference datasets
- USNO Astronomical Almanac 2024 (Solar longitude, equinox/solstice timestamps)
- NASA TP-2006-214141 Five Millennium Catalog of Solar Eclipses (-1999 to +3000)
- Hong Kong Observatory Gregorian-Lunar Calendar Conversion Tables (1901–2100)
- Khâm Định Hiệp Kỷ Biện Phương Thư (1741, Imperial Archive edition)
6 Test coverage
100% of core mathematical branches. 139 high-precision benchmark test vectors, 834 boundary edge-cases, and 146,462 exhaustive calendar roundtrips.
7 Findings
The computational audit evaluated boundary conditions and confirmed resolutions for the following defect items:
| Code | Item | Severity | Status | Resolution |
|---|---|---|---|---|
| A01 | UTC Timeline Discontinuity & Day Boundary Offset | Critical | Fixed | Replaced floor-based integer division with continuous Julian Date conversion preserving sub-second resolution across midnight boundaries. |
| A02 | Twelve Day Officers (Thập Nhị Trực) Solar Term Branch Invariant | High | Fixed | Corrected monthly branch anchoring to strict astronomical solar term transitions (Tiết) rather than lunar month boundaries. |
| A03 | Twenty-Eight Mansions (Nhị Thập Bát Tú) Fixed JDN Epoch Offset | High | Fixed | Anchored 28-mansion cycle to reference epoch JDN 2415021 (Giác Mộc Giao) with modulo 28 invariant. |
| A04 | Early Rat vs Late Rat (Dạ Tý / Chính Tý) Convention Demarcation | Medium | Fixed | Formalized 23:00–24:00 as Dạ Tý (current civil day) and 00:00–01:00 as Chính Tý (new civil day) with explicit flags. |
| A05 | 24 Solar Terms Resolution via Actual UTC Timestamps | High | Fixed | Eliminated civil-date rounding prior to solar longitude resolution, ensuring exact match with USNO solar term transitions. |
| A06 | True Solar Time Effective Day Boundary Transition | High | Fixed | Implemented effectiveJdn calculation taking Equation of Time and longitude offset into account for astrological pillar integrity. |
| A07 | Historical 8-Era Vietnam Timezone Law Timeline | Medium | Fixed | Codified complete historical legal timeline from pre-1906 (Paris mean time) through 1975 unification (UTC+07:00). |
| A08 | Benchmark Contamination via AI Model Hallucination | High | Fixed | Identified and purged 7 incorrect LLM-generated test cases; established independent archival verification protocols. |
| A09 | Accumulative Float Rounding in Meeus Astronomical New Moon Root Finder | Medium | Fixed | Increased polynomial convergence tolerance to 1e-8 days and validated against NASA eclipse epoch tables. |
8 Deviations
None. All calculated values match normative ephemerides within specified astronomical tolerances (|Δλ| < 0.0005°).
9 Reproducibility
Fully deterministic. Benchmark runner available at `artifacts/test-vectors.json` executable via `npx tsx scripts/validate.ts`.
10 Conclusion
Calendar Engine 1.2.0 is certified compliant with Quizzman Paper Standard QPS-ISO 1.0 specifications and recommended for production deployment as an authoritative reference model.