The four pillars are the year, month, day, and hour of one's birth, represented by two characters from the sexagenary cycle, one of the ten Celestial Stems and one of the twelve Earthly Branches.
The four pillars are the year, month, day, and hour of one's birth. One's birth is represented by two characters from the sexagenary cycle. One's birth is represented by one of the ten Celestial Stems. One's birth is represented by one of the twelve Earthly Branches.