The Chinese lunar calendar is the longest chronological record in history, dating from 2637 B.C. when the first cycle of the zodiac was introduced. One complete cycle takes 60 years and is made up of five simple cycles of 12 years each. The 78th cycle started on February 1984, and will end on February 2044.
Twelve animals were assigned to each of the 12 years when, according to legend, the Lord Buddha summoned all the animals to come to him before he departed from Earth. Only twelve animals came to bid him farewell. First came the Rat, then the Ox, the Tiger, Rabbit, Dragon, Snake, Horse, Sheep, Monkey, Rooster, Dog and Boar. Thus, we have the twelve animal signs of today.