This has several advantages. It allows you to be away and, secondly, especially during the winter months, you can operate the lights over the night period when electrical rates are often less. As the day-length increases in the spring months and natural light intensity improves, the period of supplying supplementary lighting can be reduced. If your plants are located in a patio having relatively good natural light, you can use the supplementary lights to extend the day-length during the early morning and late afternoon when natural light is of low intensity. Temperature. . . .
Many illustrations help to show the way.