Most of people thinks Chinese Astrology is talking about 12 animal zodiac signs. Person interesting in Chinese Horoscope always wants to know what his or her Chinese zodiac sign is before everything else. Then people quickly find out the zodiac sign is determined by Chinese calendar using their birth year. For example, 2008 is the year of Rat. The babies born in 2008 are Rat people.
I usually get emails from people confusing their Chinese zodiac sign after visiting my Chinese Fortune Calendar website, which gives them different animal sign in their birth charts. The reason is people think their zodiac signs are determined on the Chinese New Year Day from many other Chinese Horoscope sites. Chinese New Year Day is the first lunar day of the first lunar month. The Chinese New Year Day falls between mid-January and mid-February each year. That means Chinese New Year Day is from Chinese Lunar Calendar. However, the Chinese Astrology Birth Chart is from the Chinese Astrology Calendar, which is different from Chinese Lunar Calendar. The first day of the Chinese Astrology calendar is always around February 4th each year. That means Chinese Astrology calendar is based the the Sun, not Moon. Therefore people confusing their Chinese Chinese zodiac sign must be born in January or February.
Chinese Calendar is a combination calendar of Yin, Yang and Stem-Branch. Yin is the Lunar Calendar and Yang is the Solar Calendar. Stem-Branch calendar used 10 stems and 12 branches to make a cycle of 60 calendar system. 10 Stems are Male (Yang) and Female (Yin) Five Elements, which are Metal, Water, Wood, Fire and Earth. 12 Branches are 12 animals, Which are Rat, Cow, Tiger, Rabbit, Dragon, Snake, Horse, Sheep, Monkey, Chicken, Dog and Pig. 12 animals are divided into Male (Yang) and Female (Yin) groups. Rat, Tiger, Dragon, Horse, Monkey and Dog are Males, because they are in odd number sequence. All others are Females. Chicken is a female. I don't use Rooster. Cow is a female. Cow is a better term than Ox.
In the Stem-Branch system, a Male Stem must match a Male Branch; a Female Stem must match a Female Branch. That mans there is no Female Wood Rat or Male Wood Rabbit in the system. That's why is the cycle is 60, not 120. The Stem-Branch cycle begins from Male Wooden Rat and ends with Female Water Pig. Because we know Rat is male and Pig is female, so we simply say Wooden Rat or Water Pig. From year 1924 to year 1983 is a complete cycle. 1924 and 1984 are year of Wooden Rat.
One solar month might have more than 30 days. Therefore, the day counting system must be more than 30 in a month to prevent from confusing. This is why the Stem uses a cycle of 10, not 5.
Nobody knows who invented Stem-Branch. But Chinese knew about Stem-Branch before the invention of Chinese characters. They find the Stem-Branch symbols in the ancient Chinese oracle bones. At the beginning, Stem-Branch was for counting the DAY only. Later, the Yin-Yang Five-Element scholars applied Stem-Branch into a MONTH, YEAR and HOUR system. Five-Element scholars also applied Stem-Branch to the Five Elements, which are the foundation of Chinese Fortune-Telling systems.
The Chinese calendar combines the lunar and solar systems together. The Year and Day cycles use the solar system. But it has two Month cycles. One uses the lunar system and the other uses the solar system. In the lunar system of Month, the new moon day is the first day of a lunar month. The length of a lunar month is the length of time between two new moon days. The Chinese solar system divides a year into 24 solar segments according to the sun positions on the tropical zodiac (Similar to western astrology). Each segment's name was given for ancient Chinese farmers' use. Every two segments become a solar month and was assigned an Branch name. The first solar month is the Tiger month. Chinese astrology uses these solar month. Therefore, the first day of the Chinese astrology is the first day of the Tiger month, which is always around February 4th every year. When we say Chinese Astrology Calendar, we mean we use Chinese solar month calendar. When we say Chinese Lunar Calendar, we use Chinese lunar month calendar.
Why is the first month of Chinese Astrology Calendar not the Rat month? Before Shiah Dynasty (2205 B.C.), Chinese used Rat month as the first month of the year. Shiah Dynasty changed to Tiger month, so people don't have to celebrate the Chinese New Year in the cold winter. Around 1963, a Chinese Astrology Master promoted his discovery to change Rat month as the first month of the Chinese astrology year, which makes more sense from the astronomy view. But only a few of astrology masters follow the theory.
The following chart can help us to get whole picture of the Chinese Calendar.
The solar months are defined by the sun longitudes. The first month, Tiger month, begins from the Start of Spring segment or when the sun enters the 315th degree on the tropical zodiac. The second month, Rabbit month, begins from the Excited Insects segment or when the sun enters 345th degree. Again, the animal months are nothing to do with moon. Therefore, we don't need Chinese Lunar Calendar to calculate the Chinese Birth Chart.
We said Chinese Five-Element scholars applied Five Elements into Stem-Branch. Stems are 10 Yang Wood, Female Wood, Yang Fire, Female Fire, Yang Earth, Female Earth, Yang Metal, Female Metal, Yang Water and Female Water. Branches are 12 animals. Each animal contains one or more elements.
Above chart is related to Chinese calendar too. Five-Element scholars said, "One month contains 30 days. Rat month contains 30 days of Female Water; Cow contains 9 Female Water days, 3 Female Metal days and 18 Female Earth days; ...... Dog contain 18 Male Earth days, 9 Female Metal days and 3 Female Fire days and Pig contains 20 Male Water days and 10 Yang Wood days."
If all the animals can converted into Five Elements, then we can calculate the Five Element distribution in the Birth Chart. The following example is the Chinese Birth Chart of Britney Spears, who was born on December. 2, 1981.
Chicken contains Metal. Pig contains Wood and Water. Tiger contains Wood, Fire and Earth. Cow contains Earth, Water and Metal. We can see the least amount of Five Elements is Fire. Chinese Astrology is an application from Yin Yang Five Elements theory. (Other applications are Feng Shi, Chinese Herbal Medicine, Acupuncture...) Yin and Yang are talking about Balance. When Five Elements have equally powers, then they will stay peacefully. If the Five Elements in the Birth Chart has a better balance shape, then the person will be calm and quiet, which is a sign of good luck.
If the birth chart of Britney Spears can have more Fire, then her Five Elements become more balance. We call the element bring people luck as "Lucky Element". So Fire is her Lucky Element. Year of Fire is her good year. Conversely, there are too much Wood in her birth chart. Therefore, Wood is her unlucky element and will bring her bad luck. Year of Wood is her bad year.
When determining the Lucky Element is not only counting how many different element numbers inside the birth chart. We need to consider about the relationship between four seasons and Five Elements.
Solar months are derived from the sun. Therefore, we have four seasons. Four seasons are connected to Five Elements. Spring is connected to Wood, because tree grow faster and stronger in the spring. Summer is connected to Fire because of summer heat. Fall is connected to Metal, because all living things on the earth need to conserve the energy for winter (energy goes toward inside and make body hard - like flower turning into seed). Winter is connected to Water, since Winter is cold.
Where is the Earth season? The Earth season is the days between four seasons. Chinese astrology says the Earth is charge of the 18 days before each season. The Earth Cycle will repeat about every two and a half month. The total Earth days in a year is 72. The total of Five Element days in a year is 360, which is the degree of a circle and treat as a small universe.
Britney Spears was born in December. Water is cold and strong in the Winter time. Therefore, her Birth Chart is kind of cold. She needs Fire to warm up (balance) the Birth Chart. Therefore Fire can be selected as her Lucky Element. This is the "Cold and Hot" theory to study the Birth Chart. If a person was born in the winter time at night, then we can guess the Lucky Element is Fire without reading the birth chart. If the person was born in the summer time at noon, the Lucky Element probably is Water.
Chinese Astrology is Five Element application, not only animals. The secret to enter the Chinese Astrology door is the Lucky Element. The Chinese Birth Chart I mentioned here is called Four Pillars Eight Characters of Destiny. There is another popular Chinese Astrology system called Zi Wei Dou Shu, which uses many stars in the sky and is required using Chinese Lunar Calendar. If you want to learn and master Zi Wei Dou Shu, then you might have to learn Chinese language first.