Just a Little bit Confused about my zodiac sign

I am just confused if what am I going to follow my birth date is February 15, 1985 if I will follow the year when I was born my animal sign is Ox. but to some Chinese zodiac my birth date is under the animal sign rat. Most of the Feng Shui expert they just use the year to predict. What is also my complete animal if I was born under the year of fire, water, or wood?Thank You!