i alway go the last 7 days in darkness , and it does make a hell of a difference , it helps tighten up the buds and also makes the shine like hell. this info came from Soma ( soma seeds , NYC DIESEL BREEDER). i have a friend who is a very good friend of his . the reason behind this is the plant in a last gasp attempt trys to produce more flowers so it can get pollenated. now what i would say is it doesn't make the weed any stronger but what i would say is it give u the tight finished buds u are looking for . i grow WW and mate to see her in full glow before u cut her is sumthing very beautiful indeed.