We have lights on all year round on our deck. The deck has plexiglass roof, and we have a heater, so we can sit outside with all the lights on in mid winter and it's very festive. They are on a timer and go on at dusk and off around 9:30 (unless we turn them on/off at other times).
It's not so mad to want lights on at other than holiday times, and so who gives a toss what the neighbour's think - go for it!
Quote: My BiL used to have the little Christams lights in a tree by the door. They were wired to a motion sensor. They made a charming porch light.