light cycle question really good one too

ok I have 2 plants outside its is getting ready to start july I planted them may 20 the thing is im ready to start flower but the out side light cycle wont change to 12/12 until late sep early oct. is it possible for me to leave my plants out side for 12 hours of sun light and then bring them in every night for 12 hours of darkness will this still properly induce the flower stage?

Sure can. Just be sure the 12 hr light period includes either the sunrise or the sunset. Its the red spectrum of light that triggers flowering more than the dark period itself.

Yes its possible to manually give them 12/12 by covering them up with garbage bags etc but this isn't really good for the plant. You just need to be careful to avoid moisture building up in the bags as this will give you rot problems

The problem is that even a when a plant has started flowering, switching it back to 16/8 will probably just put it back into veg. I have only seen inducing flower then returning outside work twice. Once when the light outside was closer to 14/10 and once when the plants were 4/5 weeks into flower already before being put outside again.

The short answer, "YES" you can do it, and put your plants back inside for there night...
Law of unintended consequences: You are now bringing bugs into your grow room area...
Bugs lay eggs in soil and then they will hatch later and you will be blaming the soil company...
Good Luck...

there outside already so im not worried about bugs

last year I grew a plant indoors with sunlight, it was not showing gender so I started bringing it into a dark room for 10 hours/day...not ideal but it was enough to trip it....lucky for me it was a female

Leave them outside and let nature take its course as it has been done for years. You will have harvest in Sept to Nov so why rush it? If its not broke, why fix it?