These signs are rat, ox, tiger, rabbit, dragon, snake, horse, ram (sheep or goat), monkey, rooster, dog, and pig (boar). The combination of five elements with twelve animals (5 X 12) leads to the creation of the 60-year cycle. The beginning of the cycle occurs with the Wood Rat, while the culmination takes place with the Water Pig. The zodiac animal cycle of twelve is divisible by two and because of this, every zodiac animal sign can occur only in one of the two forms, yin or yang.
For example, a dragon is always yang and a snake is always yin. The current astrological cycle of the Chinese year calendar started in the year 1984. While calculating the form to which a particular sign belongs, one has to keep a simple rule in mind. When the year ends in an even number, the form is yang, while for the years ending in an odd number, the form is yin. The cycle proceeds in the following way:
- For years ending with 0, it is Yang Metal.
- For years ending with 1, it is Yin Metal.
- For years ending with 2, it is Yang Water.
- For years ending with 3, it is Yin Water.
- For years ending with 4, it is Yang Wood.
- For years ending with 5, it is Yin Wood.
- For years ending with 6, it is Yang Fire.
- For years ending with 7, it is Yin Fire.
- For years ending with 8, it is Yang Earth.
- For years ending with 9, it is Yin Earth.