when will i see sex

i have some plants growing indoors and outdoors(when its sunny) 24/0 somtimes 20/4. anyways, if i put them outside now and leave them outside when can i expect to see the sex of the plants. also, after seeing the sex of the plant can i then bring it back inside 24/0 again? i live in so cal.

dude u can. but that would be putting them into flower and back into veg. i mean u could save some stress and time just letting them get to abt 12-18" and putting them into flower to stay..

when you are old enough!

A mature plant will show sex while vegging even under 24 hrs of light, its called preflowers, usually a plant wil begin to preflower somewhere around week 5 or 6......

err right. serious answer...
if you're trying to sex them to cull the males, don't bother forcing anything. Watchhowl is right. They will show sexual maturity regardless of your light phases. They just won't flower until you decide to trigger them.
Look into preflowers and grab yourself a jewelers loop.