True solar time
The recorded local time is first resolved to UTC. City longitude and the date’s equation of time are then applied to calculate local apparent solar time before assigning the birth-hour branch.
Free Chinese Astrology Tool · 紫微斗數
Free Zi Wei Dou Shu Chart Calculator
OracleEast’s free English Zi Wei Dou Shu calculator generates a 12-palace Purple Star chart using your birth date, local birth time, birthplace and gender for decade-cycle direction. It applies historical time-zone and true-solar-time correction. Enter your email and birth details to generate your free chart. Your details are saved before the chart is displayed; no account or payment is required. The calculation conventions are stated below.
No account required
Free with your email
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.
Your chart request is saved
OracleEast has received your email and birth details. The chart is displayed here. If you need a personal interpretation, check the service scope before ordering.
Want the chart interpreted?
Review the available services before ordering. Life Map is a BaZi report; it does not automatically include a Zi Wei interpretation. Paid reports are manually analyzed, written and reviewed by a practitioner.
Choose a personal reading serviceWHY 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. A time identified as nonexistent or repeated during a daylight-saving clock change is rejected; check the recorded time or request a manual review.
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
Start with the five-step guide to read your chart. To choose between systems, compare Zi Wei Dou Shu with BaZi. For a personal reading, review the available services and what each report includes.
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.