Minimum information to prepare
Birth date
State whether the date is Gregorian or lunar. If it is lunar, confirm whether an intercalary month is involved.
Local birth time
Enter the clock time recorded at the birthplace. Do not convert it to Beijing, Hong Kong, or another region's time yourself.
Birthplace
Provide at least the city and country or region. Add context when place names are ambiguous or administrative boundaries changed.
Source of the record
Say whether the time comes from a birth certificate, hospital record, family memory, or estimate so uncertainty can be handled honestly.
Time zones, daylight saving, and civil time
The same clock time in two locations may represent different moments in universal time. Historical time-zone and daylight-saving rules also change across countries, regions, and years. A current phone time-zone setting is therefore not enough to reconstruct an older birth time.
Tian Ming Jian preserves the local clock time at the birthplace first, then checks the time zone and possible daylight-saving rule. If the place, year, or record format is ambiguous, the workflow asks for clarification rather than silently guessing.
What is true solar time?
Civil time is standardized by administrative time zones. True solar time relates to local longitude and the apparent movement of the sun on that date. Tian Ming Jian's method evaluates this type of correction before charting, with special attention to whether it crosses a traditional time-period boundary.
Method limitation: this is one charting choice used by Tian Ming Jian. It is not presented as the single rule followed by every Zi Wei Dou Shu or Bazi school. The page also avoids promising a fixed minute difference between cities.
What if the birth time is uncertain?
Search original records
Start with a birth certificate, hospital record, family handbook, photographs, or messages from the time.
Record the uncertainty range
Instead of only saying “around morning,” provide the earliest and latest plausible times.
Rule out time-zone errors
Confirm that the record is local to the birthplace and check historical daylight-saving rules.
Compare candidate periods
List structural differences between candidate charts without assuming one is correct.
Cross-observe real information
Use verifiable life information only to decide what deserves further checking, not as proof based on subjective fit.
Preserve uncertainty
When records are insufficient, deliver candidate differences and do not guarantee one uniquely correct birth time.
Fictional example: two candidate periods
Fully fictional: Sample B's family remembers that the birth occurred around dinner time. The record has no minutes, and the location used daylight saving that year.
The sound approach is to check the historical time-zone rule first, then divide the plausible range into candidate traditional periods and list how the palace and hour-pillar structures differ. If reliable records remain unavailable, the result is a candidate comparison—not a claim that the birth time has been recovered.