Most growers agree that when growing autoflowering cannabis indoors, there should be between 18 and 24 hours of light a day . The four basic light schedules growers use include: 18/6 light schedule The 18/6 light schedule refers to 18 hours of light and 6 hours of darkness. It's the most typical light cycle for autoflowering cannabis plants https://lamotagrow.com/whats-the-best-light-cycle-for-autoflowers/ Most growers of autoflowering strains prefer a light cycle of 20 hours of light and 4 hours of darkness per day. The short growth phase makes it necessary to use this time as effectively as possible and to maximise the growth of the plants.