So wait...what's my Zodiac?

June 18th, 1989 is my birth date on the Gregorian calendar, making mine the Earth Snake over in America following the standard procedure over here, but do I stick with solar or look at the chinese Lunar calendar to tell my zodiac? I'm trying to really understand it now, and its quite a challenge to figure out the outer, inner true, and secret zodiac signs...any help would be greatly appreciated