Early Flower

What is the earliest i can flower a plant, i was thinking maybe around 1 foot would that be to early? i know they double sometimes triple in size during flower.

thanks

some people put them in 12/12 from germination.

wouldnt you get barley anything for bud then??

i'd imagine it would depend on how much height you have to work with ... i started flowering at 18 days to try and keep them under 3 feet .... but since your question was how early, like monday purple said ... 12/12 from germ for either early detection of sex or to keep the plants compacted ... generally done when your doing a scrog of some sort from what i've read.