Hmmm, with room lighting probably quite a long time, thing is i get up at 0330 so the kitchen lights on for say 30-35mins while i sort out, then kids are up at 7, obviously daylight although it is a north facing window so its hardly blasting through.
I hit the sac around 830/9 and wifey comes in from work around 1030 and has her dinner, then a bit of telly and bed at maybe 1130-midnight.
The actual fish lights if you like are on maybe 8/9 hours but general light who knows. I'm thinking of setting the timer to give light from 5pm till 11pm maybe?