OK, I see. Well, that’s not something the firmware supports currently — because it’s focused on sprinkler programs, it currently only supports ‘start a program at some specific time’, run for a specific amount of time, and then stop. It’s kind of like calendar events — each event has a start time, and fixed duration.
What you want to achieve (turn lights on from dusk to dawn) is somewhat different in that the duration varies and it requires introducing an ‘end time’ . There is no reason why it can’t be supported, but it does require changing the program data structure. I will think about how to add this support.