I have a bank of blue LEDs that shines on my white ceiling in the living room. I live at a northern latitude so the big interest was in avoiding the blahs in th

I have a bank of blue LEDs that shines on my white ceiling in the living room. I live at a northern latitude so the big interest was in avoiding the blahs in the dead of winter. I initially had them on for 12 hours a day centred on solar noon. That produced a feeling I associated with spending the day out in the sun which I did not find pleasant. After some messing around I now have them turn on for 12 minutes every 2 hours during the day. The first blue light interval is an exception, it is 24 minutes. Having 12 minutes for "daybreak" just didn't seem to be enough. The only objective result I can report is that I no longer find myself opening the blinds on the living room window. Before the blue light system I used to open them daily. So ironically I now spend most of my day in semidarkness. I leave them running in the summer when the problem is an excess of light. It doesn't seem to make a difference and it means that I no longer notice when the bue light is on or off.