Chou is the second of the twelve Earthly Branches (dizhi). Its zodiac animal is the Ox, its element is Earth, its direction is north-northeast, and its double-hour runs from 1 to 3 am, the deep hours before dawn. As one of the twelve branches it combines with the ten Heavenly Stems to build the sexagenary cycle of sixty used to number years, months, days, and double-hours in the traditional calendar. The branch names the second animal of the twelve-year cycle and the corresponding month and double-hour, carrying the Ox's steady associations in the almanac. These are the conventions of the Chinese calendrical and cosmological tradition, in which the twelve branches order the animal years, the months, and the twelve two-hour periods into which the day is divided.
Chou is the second Earthly Branch, corresponding to the Ox in the twelve-animal cycle, and to the double hour from 1 am to 3 am. Its dominant hidden stem is Ji, giving it the Earth phase, though the theory of hidden stems also assigns it minor Water and Metal influences, a complexity traditional practitioners read as giving Ox-branch charts unusual internal tension between steadiness and hidden reserves. Chou is a Yin-polarity branch, so within the sixty-term sexagenary cycle it only ever pairs with the even-numbered Heavenly Stems, Yi, Ding, Ji, Xin or Gui. In the traditional Chinese calendar's fixed month associations, Chou corresponds to the twelfth lunar month, the last of the year, and in BaZi astrology a chart with Chou prominent is read through the Ox's associations of patience, diligence and a capacity to bear sustained burden, alongside a stubbornness the tradition treats as the same trait's cost.