Many websites determine a person's Chinese horoscope animal sign by the Chinese New Year's day. That means those sites tell people's Chinese astrology animal sign from their birth year.
In Chinese astrology, the animal sign represents a person is from their birthday, not the birth year. Also, the first day of the year is the first day of the Tiger month (Start of Spring), not Chinese New Year's day. Therefore, the first day of Chinese astrology year is around on February 4 every year. More...
The following tool tells your birthday's animal sign and birth year's animal sign.