complete darkness....

so when you go into 12/12 and the lights are off there is supposed to be 100% darkness with no light leaks right? well my question is if youre growing outside there is always some sort of light like the moon, street light, etc... so if there is a slight light leak like underneath the door why would that be a problem? is the no light leak for faster flowering?

If they get too much light you run the risk of the plants turning hermi. Street light are a problem. Basically it needs to be as dark or darker than a moonlit night out in the country. Just a lil light under the crack of the door would probably be alright. I keep the room door closed and also hang a blanket over it so i am at nearly 100% dark..