12/12 is the natural time that the sun is out during the fall and winter times. so the plant will respond best to natural sun times. The 12/12 tells the plant to start trying to reproduce. so unless you just want a pretty green plant to look at i would stick to just the 12/12
Mmmm, this is over-simplified to the point of being incorrect. There may in fact be only 2 days a year (one in Fall and one in Spring) that have exactly 12 hours dark and 12 hours light where you are located. It depends on your latitude as to how much sun vs. night you get, and that changes daily throughout the year. But the general point is true that MJ evolved to notice the lengthening nights, and that extended dark period triggers the hormonal reaction to flowering. In nature, flowering usually begins in late July or August in the northern hemisphere, depending on geography and strain, and at that time of year there still is more than 12 hours of light and less than 12 of dark, with the nights continuing to get longer all the way until the winter solstice (Dec 21). Indoors we use 12/12 for flowering, rather than some other light cycle, for a few reasons, but mainly because it works, period. Might a period of longer light and less dark also work? Maybe, again depends on the strain and such. So you could try it but your particular plants might not go to flower. What about shorter light and even more dark? Not necessary -- 12 hours uninterrupted dark is plenty enough to trigger any and all strains of MJ to flower, and if you cut down on light too much you aren't providing enough energy to the plant. 12/12 has been determined, through process of elimination, to be the light cycle that best balances 1) enough dark to ensure all strains are triggered to flower, and 2) enough light to keep providing energy to the plant.
Yeah i have to agree, now that i went back and read my reply i have to say it was way to over simple and straight to the simple point.