Free Zi Wei Dou Shu Chart: Time Zone, Daylight Saving and True Solar Time Handled for You
How the chart is calculated
- Turn the clock time into an exact instant using the time zone rules of the birthplace, including historical daylight saving time.
- True Solar Time = the instant + birthplace longitude × 4 minutes + the equation of time for that day.
- Find the double-hour from True Solar Time: the Zi hour starts at 23:00 and belongs to the next day, then one double-hour every two hours.
- Convert the date to the Chinese lunar calendar. Zi Wei Dou Shu uses the lunar month and day and the stem of the lunar birth year (the year changes at Lunar New Year). In a leap month, the first half counts as that month and the second half as the next.
- The lunar month and double-hour give the Life and Body Palaces; the stem and branch of the Life Palace give the element group; the group and the lunar day place the Zi Wei star; the other main stars follow; finally the four transformations and the decades are added.
What to know
- The more exact the birth time, the more reliable the chart. Near a double-hour boundary, a few minutes can change the Life Palace and every star.
- Schools differ in small ways (leap months, the late Zi hour, how some stars are placed). This page uses the common mainstream method, so other software may differ.
- This page draws the natal chart only. It has no yearly or monthly layers and gives no readings.
- Gender sets the direction of the decades: forward for Yang men and Yin women, backward for Yin men and Yang women.
- Zi Wei Dou Shu is a traditional practice with no scientific evidence of effect. Use it for cultural reference only.
Other free tools
Free BaZi calculator · Free Qi Men calculator · Why True Solar Time matters · Finding your birth hour when born abroad
FAQ
I was born abroad. Do I convert to Beijing time first?
No. Enter your local clock time and birthplace. The time zone, daylight saving time and longitude of that place and date are converted to True Solar Time automatically.
How does a Zi Wei chart differ from BaZi and Qi Men?
BaZi reads the four pillars of your birth (year, month, day, hour) for your pattern and luck cycles. Zi Wei Dou Shu places stars in twelve palaces from your lunar birthday and double-hour to show the structure of your life. Qi Men Dun Jia charts a moment and answers when and in which direction to act. They complement each other.
Why is my chart different from other software?
The most common reason is the birth time: this page uses True Solar Time (longitude and daylight saving are both corrected) while many tools use the clock time as is. The next are the late Zi hour, leap months and the school used to place stars.