how long to go

can any one help its my first grow ,I got a free seed witch I gave to a friend he built a small box and stuck in 4 20w cfl bulbs ,the seed (road runner) turned out to be a auto flower and did its own thing as this is my first grow and mine are only 20 days into bud I cant give him any advice ,I don't even know if I will tell when mine are ready his is 2 foot mine are 5 foot so there is no comparison I would guess maybe 2 weeks what do you think he isn't going to get much either