The Year Pillar changes at Lichun, around February 4, and the Month Pillar follows the solar terms. With a birthplace selected, your clock time is converted to apparent solar time using longitude, the equation of time, daylight saving, and the historical time zone.
The Day Pillar changes at 00:00. During the late Zi hour (23:00–24:00), the Hour Pillar moves to the next Zi cycle while the Day Pillar stays on the current date. See the full methodology and test cases.
How to check the result
Noon on January 1, 2000, in Beijing should return 己卯 丙子 戊午 戊午. If another calculator differs for your own birth details, compare its true solar time setting, time zone handling, and late Zi hour convention.
Frequently asked questions
Is this BaZi calculator free?
Yes. You can calculate your Four Pillars, Day Master, Ten Gods, hidden stems, and Luck Pillars without an account or payment.
Is my birth information stored?
No. This calculator runs entirely in your browser, and your birth details are not sent to Daoly or saved.
Does it use true solar time?
Yes, when you choose a birthplace. It corrects for longitude, the equation of time, daylight saving, and historical time zones. You can also calculate from clock time.
What if I don't know my birth time?
Select the unknown time option to calculate the year, month, and day pillars. The Hour Pillar will be left out, and a birth near midnight could have a different Day Pillar.
Why is gender requested?
Traditional BaZi uses it only to decide whether Luck Pillars run forward or backward. It does not affect your four pillars or your Day Master.
Daoly presents BaZi and the I Ching as cultural traditions and tools for self-reflection. Nothing here is a prediction or medical, legal, financial, or psychological advice.
