BAZI KNOWLEDGE BASE
What birth information does BaZi need? Dates, lunar months and local time
Start with the year, month and day of birth, the locally recorded clock time, and the city and country or region. Identify whether the date is Gregorian or Chinese lunar, including any leap-month designation. A record you can check is more useful than a time that has been repeatedly adjusted without retaining how it was converted.
Match the three parts of the record
Use the birth city, not your current home, and resolve same-named cities with their country or region. Use the time recorded locally at birth, not the clock in your present time zone. The table helps identify what still needs checking.
| Record | What to establish | A common gap |
|---|---|---|
| Date | Year, month, day and calendar | Entering a lunar date as Gregorian |
| Time | Local time and its approximate precision | Turning “morning” into a precise minute |
| Place | City and country or region | Selecting a different city with the same name |
Convert the whole date, not just its month number
Chinese calendar months follow lunar phases, while Gregorian months follow their own sequence and length rules. Their numbered dates do not retain the same correspondence each year. Lunar month five, day ten cannot simply be entered as 10 May; convert the complete dated record using a calendar for that year.
Clarify currently treats its birth-date input as Gregorian and has no lunar or leap-month input switch. Convert a lunar record with a reliable calendar first, keeping the original lunar date available. The software cannot infer the calendar from the numbers alone.
A leap month identifies a date, not another chart type
The Chinese calendar is lunisolar. Twelve lunar months are shorter than a solar year, so some years need an additional month. It repeats the preceding month number with a leap designation. If a year has both a second month and a leap second month, “month two, day three” needs clarification.
Check that the stated leap month exists in that year and retain its designation during conversion. Once the date is established, the BaZi month still follows its Jie boundary. A leap month does not insert another repeated BaZi month or imply a double destiny.
Keep the precision the record actually supports
A certificate saying 10:32, a recollection of “around ten,” and “sometime in the morning” have different precision. Seek the original record or the source of the recollection where possible. Removing “around” does not establish an exact minute, and noon should not stand in for a wholly unknown hour.
You do not need a full street address, a life-event history or a preferred result merely to determine the pillars. A city usually supplies a time zone and longitude; finer coordinates matter when a boundary is genuinely close. Name and occupation do not change the pillar count.
Keep the original record separate from later conventions
If a report displays apparent solar time, that is another representation derived from the record, not a replacement for the recorded clock time. Start again from the original local record when using another calculator. An already corrected input can otherwise receive the correction twice.
Sex does not determine the four natal stem-branch pairs themselves. Some traditions use it later for luck-cycle direction. Separating those steps explains why a later calculation may request information that is not needed for the natal pillar count.