Hi With auto-flowering strains you can leave the lights on any schedule you like. Some people prefer 24/0 so as to give the plants as much light as possible. 20/4, 18/6 are also common for autoflowering, for different reasons. It can save money on electricity and some people believe they need a certain rest period. I've heard that plants focus on making energy during the day and using the energy at night so that could be true. This guide helped when I was growing weed www.thegreenpagesgrowguide.net