More then 12 hours of light

I was reading a jorge cervantes something or other and saw something about how people will put there plants into flower for a while and then after they have been flowering for some time will give the plants more then 12 hours of light a day.

This got me thinking, if I had the light on 18 hours a day for the last week of the grow would it make them finish faster or would I get more anything? Would it make them hermie out?

Maybe a really bad idea but has anybody done this?

more than 12 hours will make it revert back to the vegetative grow state. if it's late enough in the flowering cycle, you will just end up with a hermie.

Makes sense. I need to find that artical I read that in to figure out what he was talking about. I think something about growing outside perhaps.