4F1M6answered grow question 4 years ago Personally I feel as though even autos need some rest(lights off) time. Though I've ran autos 24 hours to success... I've had much better results running them 20/4 their whole life. But 2 make a long story short u can run autos 24 hours there whole life so there is no week u need to change that. If ur running photoperiod plants. 18 hours light all of veg. 12 hours for flowering.