The Chinese zodiac's complete animal-and-element cycle lasts 60 years.
The cycle combines 12 animal signs with 10 heavenly stems, which are arranged through the five elements in yin and yang forms. The least common multiple of 12 and 10 is 60, so the same animal-element pairing returns only after six decades.
For example, a Wood Dragon year and a Fire Monkey year are not just animal labels; each is one particular combination in the longer cycle. The 2024 Wood Dragon year followed 1964's Wood Dragon year, exactly 60 years earlier. This is why traditional calendars can distinguish people who share an animal but have different elements.
The 60-year cycle is also called the sexagenary cycle and has been used in Chinese calendrical and historical records for centuries. In popular conversation, people often shorten a designation to “Dragon year” or “Rabbit year,” but that wording omits half of the traditional animal-and-element information.