True solar time
The city longitude is used to correct clock time into local apparent solar time before the birth-hour branch is assigned.
Free Chinese Astrology Tool · 紫微斗數
Free Zi Wei Dou Shu Chart Calculator
Generate your 12-palace Purple Star chart instantly. Built around the core chart-setting rules taught in Ni Hai-Shia’s Tian Ji framework, with historical time-zone and true-solar-time correction.
No account required
No email gate
Historical DST handling
True solar time
CAST YOUR NATAL CHART
Your birth moment, placed into twelve palaces
Country and city are used only to correct the historical civil time and local solar time. Exact birth time matters because a two-hour change can move the Life Palace.
Swipe left or right to see the whole 4×4 chart.
Calculation, not an automated fortune verdict. This free tool places the natal palaces, principal stars, selected auxiliary stars, Four Transformations and decade cycles. A paid reading is manually analyzed, written and reviewed by a practitioner — it is not an AI-generated report.
Save your chart for follow-up
Optional. Submit your name and email only if you want OracleEast to retain these birth details and contact you. Success is shown only after the backend confirms receipt.
Want the chart interpreted?
Order a human-prepared Life Map reading. Your chart is reviewed in context, then the report is manually written and checked before delivery.
Get a personal Life Map readingWHY THIS VERSION IS DIFFERENT
Three calculation details that prevent common wrong charts
Historical time zones
The browser’s IANA time-zone database is used for the birth date, including historical daylight-saving rules where available.
Ni-school boundaries
A leap lunar month is treated as the following month. A true-solar late-Zi birth from 23:00–23:59 uses the previous chart date.
NEW READING GUIDE
How to read the chart you just generated
Use the OracleEast five-step method: verify time, locate Life and Body, read San Fang Si Zheng, add star functions, then add timing.
Read the five-step Zi Wei chart guideQuestions before you calculate
What if I do not know my exact birth time?
Zi Wei Dou Shu is highly sensitive to the two-hour birth period. Use the closest reliable time only as a provisional chart. If the time could cross a branch boundary, a manual rectification is safer than pretending the chart is certain.
Why do you ask for country and city?
They are needed to determine the historical time zone and longitude. The free calculator does not ask for a street address, company or phone number.
Does this page give an AI reading?
No. It calculates and displays the chart. OracleEast paid reports are manually analyzed, written and reviewed by a practitioner.
Can two schools produce different charts?
Yes, especially for leap months, Zi-hour boundaries and time correction. This tool states its rules openly so the result can be audited.