Is it ok to leave black dye henna in your hair all night?

So i want to dye my hair BLACK, with henna (henna el captain), and im not sure what to do.. what do i mix in it, how long do i leave it in for, and doest the amount of time i leave it in for affect the coloring (is it bad for the hair?) i have hair that reaches to about 4 inches from my shoulders? any recipies? i have eggs, olive oil, water(ovcourse), and lebne(if anyone knows what that is... it is this curdled milk cream that is soo good with peta bread, olive oil, and tomato's,,, its middle eastern, im lebanese so i eat LOTS :D idk if it CAn be used withe henna)