Case 01 of 26
Solar-term boundaries
Before Lichun: the Bazi year has not changed
A February date can still belong to the preceding Bazi year.
Boundary question
Does the Year Pillar wait for Lichun instead of changing on January 1?
Yes. This record remains in the Yi-Si (乙巳) year and Ji-Chou (己丑) month before the 2026 Lichun boundary.
Synthetic input
Recorded facts
- Date
- 2026-02-03
- Recorded time
- 12:00
- Location
- 120°E reference meridian
- Time zone
- Asia/Shanghai
- Longitude
- 120.0000°
- Gender input
- Male
Pinned expected facts
Verified output
Year
乙巳
Month
己丑
Day
戊申
Hour
戊午
- Day Master
- 戊
- True solar time
- 2026-02-03 11:46
- Total correction
- -13.48 minutes
- Historical offset
- UTC+08:00 · DST 0 min
- Luck direction
- 逆排
- Reference Jie
- 小寒 · 2026-01-05 16:23:10
- Luck start
- 2035-09-10 10:28:31
Conventions and limits
What this case does — and does not — prove
It verifies
Deterministic reproduction of this input under the named engine version and conventions. A pinned-field mismatch stops the production build.
It does not claim
Universal agreement across Bazi schools, interpretation of a real person, or certainty where the historical record is incomplete.
tyme4ts 1.5.2 · cantian-tymext 0.0.27 · sect 2 day boundary · BaziCalculator.ai NOAA/IANA true-solar adapter
calculation-benchmarks-v1 · reviewed 2026-09-05