A little bit of Sheep and a little bit of Monkey equals Golden Sheep?

I was born on January 11, 1980, i don't know if it was Chinese calender or Western calender but I was born in Hong Kong. Some say it is Monkey while others say it was Sheep because Chinese new year doesn't happen until 2/16/1980 in Western Calenders. Any help? Just want to know a little more, thanks