My long time partner was very much into Astrology and was in-fact a Moon worshiper. She had a knack when it came to deciding what Star Sign influenced someones character.
Fortunately more information is needed when determining someones birth chart accurately, such as the placement and effects of planets and other celestial bodies etc.
Of course if you just want to state your birthday for whatever reason then go for it.
I was born just after 6pm on 28th Nov. My mum remembers because she was watching her favorite program on tv apparently.