This is a much debated topic but when did you start your flowering count? When it showed sex or when you switched your lights? I have found thru my own grows that if I start the count when the plants show sex, I am closer to the breeders recommendations. Remember now they are advertising this off of grows in near perfect conditions. 9 weeks is a general time that you can use to prepare with. Sometimes its sooner but more often than not, its longer.