Case 10 of 26

Historical time zones

Singapore: no daylight-saving adjustment

A stable UTC+08:00 zone separates longitude correction from DST.

Boundary question

Does the receipt avoid inventing DST where none applies?

Yes. The DST component is zero; longitude and Equation of Time still move noon to 10:55.

Synthetic input

Recorded facts

Date
1990-06-15
Recorded time
12:00
Location
Singapore
Time zone
Asia/Singapore
Longitude
103.8198°
Gender input
Male

Pinned expected facts

Verified output

build verified

Year

庚午

Month

壬午

Day

辛亥

Hour

癸巳

Day Master
True solar time
1990-06-15 10:55
Total correction
-64.75 minutes
Historical offset
UTC+08:00 · DST 0 min
Luck direction
顺排
Reference Jie
小暑 · 1990-07-07 17:00:28
Luck start
1997-11-15 21:21:15

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