To quote the HERBAL EXTENSIVE AUTHORITY:

"Moving the plants to 10-13 hour light periods (moving it outside) with uninterrupted darkness (no bright lights nearby) will force the plant to flower. It will ripen and be 2-3ā?? when ready to harvest. When a plant is moved from continuous indoor light to a 10-13 hour day outside, it will start to flower in anticipation of oncoming winter. Vegetative starts moved outside March 1st, will be ripe by May 1. Vegetative starts moved outside on May 1 will be ripe by July 1. Starts moved outside September 1 are picked by Nov. 1st. In Winter, operations are moved indoors and a crop is planted for seed in anticipation of planting outdoors the next summer, or just for some extra winter stash.
Keep in mind that the ā??manā? is looking for plants in the Sept./Oct./Nov. time-frame, and may never notice plants placed outside to flower in April. Be smart, make your big harvest in May, not October!"

My bible says differently. I guess its all in how your faith lies.

Happy Growing.