About

Zi Wei Dou Shu (Purple Star Astrology) is one of the most respected forms of Chinese fortune-telling, historically reserved for the Imperial Court. Unlike BaZi (Four Pillars of Destiny), which relies primarily on solar terms and elemental balance, Zi Wei Dou Shu constructs a sophisticated celestial map based on the Lunar Calendar. It models a person's life using a fixed grid of 12 Palaces, populated by stars from the North and South Dippers.

This calculator solves the complexity of manual chart plotting by integrating a 100+ year Ephemeris algorithm. It precisely converts Gregorian dates to the Chinese Lunar system - accounting for leap months and solar alignments - to determine the exact placement of the Emperor Star (Zi Wei) and its 13 accompanying major stars. This tool is essential for practitioners requiring high-precision charts for analyzing destiny, career paths, and karmic connections.

Formulas

The core of the chart depends on locating the Life Palace (Ming Gong). This is derived from the Lunar Birth Month and the Birth Hour Branch.

Given:

m = Lunar Month Number
h = Birth Hour Branch Index (1 for Zi, 2 for Chou, ..., 12 for Hai)

The position of the Life Palace (P) on the Earthly Branch map is:

P = m − h + 1 (modulo 12 adjustments apply)

Once the Life Palace is set, the Five Element Bureau is calculated based on the Heavenly Stem of the Life Palace and its Earthly Branch. This Bureau number (B ∈ {2, 3, 4, 5, 6}) is strictly required to determine the location of the Zi Wei star relative to the Lunar Day (d).

Approximation for Zi Wei Position (Z):

{

Z is found such that Z × B ≥ dSpecific remainders determine offset

Reference Data

Star Name (Pinyin)	English Title	Element	Type	Key Characteristic
Zi Wei	The Emperor	Earth	North Dipper	Leadership, dignity, resolving difficulties.
Tian Ji	The Advisor	Wood	South Dipper	Strategy, intelligence, movement.
Tai Yang	The Sun	Fire	South Dipper	Status, male relatives, public service, radiance.
Wu Qu	The General	Metal	North Dipper	Wealth, action, decisiveness, finance.
Tian Tong	The Child	Water	South Dipper	Lucky, relaxation, emotional, social.
Lian Zhen	The Diplomat	Fire	North Dipper	Complex emotions, career ambition, blood relations.
Tian Fu	The Treasury	Earth	South Dipper	Stability, property, conservative wealth.
Tai Yin	The Moon	Water	North Dipper	Wealth accumulation, female relatives, gentleness.
Tan Lang	The Wolf	Wood / Water	North Dipper	Desire, socialization, metaphysics, indulgence.
Ju Men	The Gate	Water	North Dipper	Communication, scrutiny, mouth-related issues.
Tian Xiang	The Minister	Water	South Dipper	Service, support, seal of authority, neutrality.
Tian Liang	The Sage	Earth	South Dipper	Protection, longevity, medicine, teaching.
Qi Sha	The Power	Metal / Fire	South Dipper	Authority, risk-taking, turbulence, command.
Po Jun	The Pioneer	Water	North Dipper	Destruction, rebuilding, innovation, changing norms.

Frequently Asked Questions

Western calendars (Gregorian) are solar-based. Zi Wei Dou Shu is strictly a Lunar system. A person born on the 5th of a Gregorian month might be born on the 12th, 13th, or even a different month in the Lunar calendar. Without precise algorithmic conversion (handling leap months), the entire star distribution will be incorrect.

Zi Wei Dou Shu relies on True Solar Time (or at least Standard Astronomical Time). If you were born during DST, you must subtract 1 hour from your clock time. Additionally, for maximum precision, some masters adjust for longitude relative to the time zone meridian.

The Life Palace (Ming Gong) represents your innate destiny, personality, and potential at birth. It is the "Pre-Heaven" luck. The Body Palace (Shen Gong) represents your actions, obsession, and how your destiny evolves after mid-life. It acts as a modifier to the Life Palace.

The birth hour determines the placement of the Life Palace. Without the hour, you cannot generate a valid Zi Wei Dou Shu chart. A chart generated with just the date would only yield the "Four Pillars" (BaZi) data, not the 12 Palaces.

Yes. The underlying database engine checks specific hex-codes for every year between 1900 and 2100 to determine if a Leap Month occurred and which month it was. If your birthday falls in a leap month, the calculator adjusts the star placements according to standard ZWDS rules (usually mapping to the previous month or using specific leap-month logic).