I don't mean to challenge you here Leprechaun cuz I know all strains are different on timing, and I agree with what you said so far, I just wanted to throw in a little piece myself too. I was just gonna say that, being some strain's timing varies greatly, you could potentially see the sex of your plant in about one week. I have a hybrid I've been growing for a while now and it takes 7 days to show pistils once I move it from 20/4 to 12/12. If I were to let stuff wait 3 weeks without knowing the sex, and it turned out to be male.. 3 weeks would be enough time to almost be ready to release pollen. I just wanted to make sure that he doesn't go and ignore it for two weeks and then check for signs of gender. Its good to keep an eye on it, looking closely every few days or so.

The thing most people don't seem to understand about determining the gender of your plants is that if you just look at some pictures of early flowering males/females, you'll know what to look for, and your plant will clearly show it to you when its ready. And if you can't clearly tell what gender it is, then its way too early to cause a problem anyways. People get too scared about males when they first start growing, which is understandable, nobody likes to get a bag full of seeds, but new growers quickly realize its a much easier thing to figure out than they first thought.