I wouldn't be switching you light cycle back and forth too much if I were you. Either veg or flower. Don't keep changing your mind, thatll give you nothing but hermies. And keep in mind... dark time = very dark time. If you must look when they are sleeping, use minimal light for a super fast time. No dinking around in there. And no light peeping through door cracks either.
Let me explain how a plant 'works', and that will explain alot. During the dark hours, your plant processes sugars which in turn is what causes the flowering stage. I don't know if you need 12 hours of darkness to flower, do what works, at least 12 hours of darkness. People have different opinions about whether a longer dark period will mature your plant faster, but logic tells me yes, and so do a few other growers. They say it cuts down on your yeild, which logic also tells me is correct.
photosynthasis = growth
darkness = sugars
I recomend you go straight 24 hours of light for veg, and at least 12 hours of darkness for flower.