Chou is the second Earthly Branch, belonging to Yin Earth, associated with the Ox zodiac sign, and corresponds to the Chou Hour (01:00–03:00). Chou Earth represents frozen earth of deep winter, internally concealing Gui Water, Xin Metal, and Ji Earth; it is cold, damp, and heavy in nature, symbolizing diligence, endurance, and the power of accumulation. Chou Earth functions as the 'Treasury of Metal', embodying the imagery of storage and preservation.
Chou Earth is identified from the Earthly Branches of the Four Pillars in a Bazi chart. If Chou appears in the Year Branch, the native belongs to the Ox zodiac; if Chou appears in the Day Branch, the Spouse Palace is Chou Earth. Chou Earth is strongest during Chou Month (the twelfth lunar month), when it is in season.
A person born on a Yi-Chou Day has Chou Earth as Indirect Wealth in the Day Branch, suggesting a spouse skilled in financial management and household stewardship.