The traditional 60-year cycle combining Chinese zodiac animals and elements is called the sexagenary cycle.
It is formed by combining 10 heavenly stems with 12 earthly branches. The stems are associated with the five elements—Wood, Fire, Earth, Metal, and Water—with each element appearing in yin and yang forms. The branches are represented by the 12 zodiac animals. Because 10 and 12 share a least common multiple of 60, the complete stem-branch sequence repeats every 60 years.
The cycle is also called the ganzhi system. It has been used in Chinese calendrical notation for years, months, days, and sometimes hours. A year’s animal alone identifies only a 12-year position; the stem-branch pair supplies the additional element and polarity information.
The sexagenary cycle is not simply a 60-animal list. It is a structured combination of two shorter cycles, which is why the same animal and element pairing returns after 60 years.