Counting and calculating

Combined with the twelve branches in a fixed rotation, the ten stems produce the sixty-year cycle that names Chinese years, and in Ba Zi (the Four Pillars of Destiny) the stem and branch of the year, month, day and hour of birth are read for character and fortune. The stem-and-phase pairing ties the calendar directly to the five-phase cosmology.

The atlas gives each stem its phase, polarity and use. The earthly branches it pairs with, and the wu xing phases it expresses, are treated in their own categories under Eastern Systems.