Calculator Input
Example Data Table
| Example | Date | Time | Rule | Use Case |
|---|---|---|---|---|
| Standard adult chart | 1990-05-15 | 08:30 | Solar-year pivot | Checks all four pillars with morning hour branch. |
| Near year boundary | 2001-02-02 | 21:20 | Solar-year pivot | Shows why early February needs a year rule. |
| Late Zi hour | 1988-09-10 | 23:25 | Next-day Zi option | Tests charts where day handling may differ. |
Formula Used
1. Year Pillar
The calculator uses the sexagenary cycle. The stem uses (solar year - 4) mod 10. The branch uses (solar year - 4) mod 12. With the solar rule, dates before about February 4 use the previous solar year.
2. Month Pillar
Month branches follow approximate solar-term boundaries. The Tiger month starts near February 4. The first month stem depends on the year stem. Then the calculator advances one stem for each solar month.
3. Day Pillar
Day pillars repeat every 60 days. This page uses October 1, 1949 as a Jia-Zi reference day. The date difference is reduced by modulo 60.
4. Hour Pillar
The hour branch changes every two hours. Zi covers 23:00 to 00:59. The hour stem depends on the day stem group.
How to Use This Calculator
Enter the birth date first. Then enter the birth time from the local birth place. Add a place label if you want it in the export. Choose the solar-year rule for Four Pillars style work. Use the simple Gregorian rule only for casual zodiac checks.
If the time is between 23:00 and 23:59, choose the Zi hour option that matches your preferred school. Some methods keep the same civil day. Other methods move the chart to the next day. After calculation, review the Year, Month, Day, and Hour rows.
The Day Master is the heavenly stem of the Day pillar. The element balance table counts visible stems, branches, and hidden stems. Use the CSV export for spreadsheet storage. Use the PDF export for a quick report.
Chinese Zodiac Pillars Guide
What the Four Pillars Show
Chinese zodiac pillars are built from time. A complete chart uses the year, month, day, and hour. Each pillar has a heavenly stem and an earthly branch. The branch also carries an animal sign. Together, they create a symbolic map of elements, polarity, and seasonal force.
Why Stems and Branches Matter
The ten stems show Wood, Fire, Earth, Metal, and Water in yin or yang form. The twelve branches show animals, directions, seasons, and hidden stems. A pillar is not only an animal. It is a layered symbol. This is why two people with the same animal can still have different charts.
The Day Master
The Day stem is often called the Day Master. Many readers use it as the center of the chart. It describes the element being compared with the rest of the pillars. For example, a Wood Day Master is read against Fire, Earth, Metal, and Water around it.
Element Balance
Element balance is a helpful starting point. A repeated element may show strong emphasis. A missing element may show a quieter theme. This calculator counts visible stems, branch elements, and hidden stems. It gives hidden stems a smaller weight because they are less direct.
About Accuracy
Traditional BaZi charts can use exact solar terms. This page uses fixed approximate dates for speed and clarity. It is useful for study, comparison, and educational content. For formal readings, verify the chart with precise astronomical solar-term data.
FAQs
1. What is a Chinese zodiac pillar?
A pillar combines one heavenly stem and one earthly branch. The branch also has an animal sign. Four Pillars use year, month, day, and hour.
2. Is this the same as my zodiac animal?
No. The animal is only one part. A full pillar also includes a stem, element, polarity, hidden stems, and timing context.
3. Why does February affect the year pillar?
Many Four Pillars systems use the solar year. It starts near February 4. Births before that point may use the previous pillar year.
4. What is the Day Master?
The Day Master is the heavenly stem of the Day pillar. It is often used as the main reference point in a chart.
5. What are hidden stems?
Hidden stems are stems stored inside each earthly branch. They add extra elemental detail beyond the visible stem and animal sign.
6. Should I use the late Zi option?
Use it if your preferred method treats 23:00 to 23:59 as the next day. Leave it unchecked for civil-day handling.
7. Are the month boundaries exact?
This calculator uses fixed approximate solar-term boundaries. Exact BaZi work may require astronomical solar-term times for the birth year and location.
8. Can I export the results?
Yes. Use the CSV button for spreadsheet data. Use the PDF button for a simple printable report.