Astrology tools rarely show their working. Here is ours, the exact sequence the calculator runs, matching the classical plotting method. Every step below is deterministic: the same birth data always produces the same chart.
Your solar date is converted to the Chinese lunar calendar using a year-by-year table covering 1900 to 2100, including leap months. The lunar month and day, the year pillar and the double hour drive everything that follows.
Starting from the Yin position, count forward one palace per lunar month, then backward one per double hour. Where the count lands is the Life Palace. The Body Palace uses the same month count but moves forward with the hour instead.
From the Life Palace, the remaining eleven palaces are laid counter-clockwise in fixed order: Siblings, Spouse, Children, Wealth, Health, Travel, Friends, Career, Property, Fortune, Parents.
The Life Palace acquires a heavenly stem from the birth year via the five tigers rule. That stem-branch pillar maps through the Na Yin table to one of five bureaus: Water 2, Wood 3, Metal 4, Earth 5 or Fire 6.
The lunar day is divided by the bureau number. The quotient and remainder, handled by the classical odd-even correction, fix the position of Zi Wei, and the rest of its series (Tian Ji, Tai Yang, Wu Qu, Tian Tong, Lian Zhen) follows at fixed offsets.
Tian Fu sits at the position mirroring Zi Wei across the Yin-Shen axis. Its series (Tai Yin, Tan Lang, Ju Men, Tian Xiang, Tian Liang, Qi Sha, Po Jun) fans out from it in order.
Wen Chang and Wen Qu from the birth hour, Zuo Fu and You Bi from the month, Lu Cun, Qing Yang, Tuo Luo, Tian Kui and Tian Yue from the year stem, Huo Xing and Ling Xing from year branch plus hour, Tian Ma from the year branch trine, Di Kong and Di Jie counted from Hai.
The birth year stem selects four stars for Lu, Quan, Ke and Ji according to the standard table, marking the chart’s permanent activation set.
The bureau number sets the starting age. Yang-year males and yin-year females run the decades clockwise from the Life Palace; the others run counter-clockwise. Each decade palace carries its own stem for decade transformations.
The current year’s branch picks the palace hosting the annual Life Palace, and the year’s stem fires the annual transformations, including the annual Ji and its clash.
The AI Life Story adds no arithmetic. It receives the finished fact sheet, palaces, stars, frames, transformations, patterns, and writes prose under instructions that forbid it from placing any star the engine did not place. Interpretation is generated; the chart never is.
Ten steps, one chart.
Run Them On Your Birth Data