AOL: A Complete Guide to the 12 Chinese Zodiac Signs, from Personality to Compatibility Chinese astrology — also known as Shu Xiang — dates back more than 2,000 years. Similar to traditional Western astrology, the Chinese zodiac has 12 zodiac signs that can determine a person's ... A Complete Guide to the 12 Chinese Zodiac Signs, from Personality to Compatibility "Birthdate" as a compound word is more common on official forms and in writing.

Understanding the Context

Birth date may be the way that it is spoken by most English speakers, who rarely use it as a compound word. If its usage is for a database then it would be best to stick with using "birthdate", the compound word.