Case 05 of 26

Solar-term boundaries

Before Qingming: Gregorian April is still Mao month

April 4 remains on the pre-Qingming side of the month boundary.

Boundary question

Can an April record still have the Mao Month Pillar?

Yes. The Month Pillar remains Xin-Mao (辛卯) until Qingming arrives.

Synthetic input

Recorded facts

Date
2026-04-04
Recorded time
12:00
Location
120°E reference meridian
Time zone
Asia/Shanghai
Longitude
120.0000°
Gender input
Female

Pinned expected facts

Verified output

build verified

Year

丙午

Month

辛卯

Day

戊申

Hour

戊午

Day Master
True solar time
2026-04-04 11:56
Total correction
-3.44 minutes
Historical offset
UTC+08:00 · DST 0 min
Luck direction
逆排
Reference Jie
惊蛰 · 2026-03-05 21:59:00
Luck start
2036-02-14 07:02:33

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