At this time of day, we normally shower, put on our PJs, and either watch one hour of TV, brush our teeth, floss and go to bed. At this time, he comes out of the shower, gets dressed as if to go out. Sometimes showers a second time, I can’t ask him to do anything, he would get agitated.
The medical community really doesn't know why it happens. It could be how the demented mind interprets light, it could be they are more tired and anxious as the day progresses... there is not real way to study it since people with dementia cannot accurately answer questions and oftentimes don't interpret their body signals accurately anymore.