For a long time my kids were up at 5am or earlier. I mean, they still are, but I'm not always awake to observe them since we use a clock system and they stay in their room until later. That said, I would defonitely include 5am in the morning time slot, and potentially 4am. I know to some degree, we are an outlier, and not many will be logging behaviors during that time, but I still don't consider 5am to be "night"