The 12 hour rule doesnt really apply to outdoor plants, it is a whole mess of things. The days getting shorter, the sun changing colors, the cooling down at night etc. Around here, they usually start flowering when they still have 13+ hours of sunlight. Mine are stretching, but no flowers yet. Mine usually start putting out flowers around mid august and harvest around halloween. This is my third or fourth season outside West side of Denver.wont be 12hour nights till sept in the denver, co area