I always take the breeder's growth timeline and just assume that means "once it starts growing calyxes". In the case of most of the Dragon Master seeds (formerly Wiz, formerly Mossy...now Auntie Mossy, lol) I see them start to throw pistils and develop calyxes around week 5. From there, it's usually 6-10 weeks harvest, depending on strain (Purple AK47 takes a lot longer than JEM). 11 weeks seed to weed is better than most photos grown under 12/12, and will net you more pot with a 20/4 or 24/0 light cycle. To me, her timing is almost dead on based on the limited number of plants I've grown (10, 6 of which were culled after sexing). I use my experience with those autos because they're relatively fast flowering plants within the "worth your time to grow" category of autoflowers. Many of the big name commercial seedbanks claim 6-8 weeks seed to weed, which is incredibly optimistic for a rooted clone, let alone a seed plant.
Anyway, what are your grow conditions? What nutes are you using? We can advise if you offer more detail.