Case 16 of 26
Zi Hour and midnight
After 23:00: Zi Hour begins without changing the day
The paired case crosses 23:00 but stays before civil midnight.
Boundary question
Does Zi Hour begin while the sect 2 Day Pillar remains unchanged?
Yes. The Hour Pillar changes to Jia-Zi (甲子), while the Day Pillar remains Wu-Wu (戊午).
Synthetic input
Recorded facts
- Date
- 2026-06-13
- Recorded time
- 23:15
- Location
- 120°E reference meridian
- Time zone
- Asia/Shanghai
- Longitude
- 120.0000°
- Gender input
- Male
Pinned expected facts
Verified output
Year
丙午
Month
甲午
Day
戊午
Hour
甲子
- Day Master
- 戊
- True solar time
- 2026-06-13 23:15
- Total correction
- 0.29 minutes
- Historical offset
- UTC+08:00 · DST 0 min
- Luck direction
- 顺排
- Reference Jie
- 小暑 · 2026-07-07 09:56:57
- Luck start
- 2034-04-06 10:35:17
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