there are numerous factors involved in answering your question.... every strain is different and flowering times will vary and seeing as you are using bagseed there is really no way to tell... but figure roughly 7 to 10 weeks. You will then have to factor in the amount of time you keep them in vegetative growth.... so if you veg them for 3 weeks and then switch to 12/12... you can figure ROUGHLY 10 to 13 weeks... if you notice the leaves are fat implying an indica dom strain you can go with the lower estimate of that scale... more sativa dom and I would suspect the higher... but that is not set in stone... like I said.... varies quite a bit, but that should give you a basic guideline~