I run a website and I notice a peak about 9.00 a.m. before then it is pretty quite, traffic reduces steady until about 8.00 p.m. when it peaks again. Keeps fairly busy until about 11.00 p.m. it then drops off.
I imagine the morning peak is because that is when people start work. The evening probably because people have come home and had their evening meal and then go on the internet.
Quietest days are Friday and Saturday on my site.