Input guide
Birth Details for a Bazi Calculator
Direct answer
Use a Gregorian birth date, the local clock time recorded at birth, and the IANA timezone of the birthplace. If the time is unknown, say so; an hour pillar should not be invented.
Use the birth record, not today's location
Enter the Gregorian date and 24-hour clock time used at the place of birth. Do not first convert it to Beijing, UTC, or the place where you live now. Select the birthplace's region timezone, for example America/New_York. A city label is optional; it does not replace timezone selection.
The form does not ask for a name, email, gender, precise address, or question about your life. No geocoder is used. The chosen timezone is enough for this civil-clock method, which does not apply true solar-time correction.
When birth time is missing or approximate
Choose “I don't know my birth time.” The calculator leaves the hour empty. If the date crosses a month-opening solar term, it also shows possible year/month pairs. Do not enter noon just to fill the box: that would imply a known hour.
If a record is approximate and close to 23:00, midnight, a two-hour boundary, or a displayed solar-term instant, compare neighboring inputs and keep the uncertainty in view. We do not infer or rectify a birth time from life events.
Daylight-saving changes
The selected IANA region supplies historical offsets and DST. A nonexistent clock time is rejected. When a clock time occurred twice, open the repeated-time option and select the first or second occurrence only if the record supports that choice. Use a recent browser and check historical sources when uncertain.
Privacy and limits
The calculation stays in this browser tab. No birth details are sent to analytics, AI, a database, or a mapping provider. Clearing the form or reloading removes the details from the app; browser form history is controlled by your device. See privacy details and the calculation method before interpreting the result.