OH, if you want to flower early you can do this.. I have seen 2 very succesful techniques.

1. bring the plants next to a building.. This will cast a shadow on the earlier in the day.
2. I saw a simple cloth barrier built around plants.. the cloth was GREEN...and blended well with the surroundings.. It was actually a mesh folded over a few times to prevent light from coming in..

both these methods allowed the plants to mature early... I would guess about 10-20 days faster