I'd like to use 3 profiles. One that is in effect from sunrise to sunset. Another that is from sunset to 11 PM and finally one that is from 11 PM to sunrise. Is this possible? Thanks!
You can definitely do that. As you see below, I use only 2 schedules. But you can select more and "draw" them in to the days/times you would like. The Blue Iris help file also has good information on scheduling in it as well.
That is doable. When you add the mark on the schedule, you just check the box "relative to sunrise/sunset". For your 11PM mark, you would uncheck the box.
I believe you can just set up one day and then copy it to all the other days.