Nine Star Ki Calculator: Year, Month and Third Number
Nine Star Ki uses a birth-year number, solar-month number and a derived third number. This calculator uses the same year number for all sexes and the year-plus-five-minus-month third-number rule.
1 · 5 · 1
Year: 1 Water · Month: 5 Earth · Third: 1 Water
1 + 5 − 5 = 1, reduced to 1. Year pillar 庚午; solar month 辛巳.
Year and solar month
The year number descends by one each year and changes at Li Chun. The month number follows a descending solar-month cycle. Births near a term boundary need the recorded clock time.
The third-number rule
Reduce year number plus five minus month number into the range one to nine. The third number is derived from the first two; it is not a separate birth-hour number.
Nine numbers and five phases
One is Water; two, five and eight Earth; three and four Wood; six and seven Metal; nine Fire. A number and its phase correspondence give two ways to follow the same nine-position system.