Chinese Astrology is based on its LuniSolar calendar system. This calendar system is totally different to that of Western Gregorian calendar and Tamil Calendar (Indian Panchangam system).
Chinese astrology has 12 animal signs. Each sing has five sub divisions. Each sub division is called elements.
The 12 Chinese horoscope animals are: Rat, Ox, Tiger, Rabbit, Dragon, Snake, Horse, Goat, Monkey, Rooster, Dog, Pig. The 5 elements are Metal, Wood, Water, Fire and Earth.
These animals and elements sub classification as Ying and Yang. Ying has male character while Yang represents female character.
Few animal signs are friendly to each other while few are nuetral, while few others are enemies. Same way, elements. For example, Wood is enemy to Earth, as wood pierces into earth. Fire is opposite to water.
Each animal sign has a set of character and each element has a set of character. For example, Earth means Kindness and Leader. Monkey sign represents brilliant, energetic, ready to face challenges.
As said, each animal sign has an element with it. Every year is named with an animal and an element. For example, the year 2000 is Metal Dragon (Metal is the element while Dragon is the animal).
Those who were born in the year 2000 have their Chinese Zodiac sign as "Metal Dragon".
To be noted here is, every month, every day, every hour is named using this same system. For example, a person born on 1st December 2019 at 08.59 AM will have "Wood Dragon" as hour pillar, "Water Monkey" as day pillar, "Wood Pig" as month pillar and "Earth Pig" as year pillar.
Chinese follow a 60 year cycle for naming the years. That is, each animal along with one element will have the first cycle. Same way it follows for the next elements. There by 12 years X 5 elements makes to 60 years. In case of years, Ying Yang is not considered.
For months, each element will have its Ying Yang - Male feature followed by Female feature, so one element repeats for 2 consequtive months. As discussed, Chinese calendar uses LuniSolar system. That is they take Lunar cycles for calculating months. So, in few years, there will be 13 months while few others have 12 months. While the year has 13 months, naming of months will follow Solar calculation. That is, Chinese have 12 seasons and each season has an animal, while elements keep cycling.
Predictions, zodiac calculations, match making, lucky number calculation, lucky color all depend on animal and element cycles.