In Visitor log you can scroll down and click "next"-Button to see the visits before (within selected period) After having done this you scroll up again to have a look the first visits of the selected period again. => Then you noticed you can't. So you have to scroll down again and click "before" there.
Because the visitor log website is relatively long, it would be better a) to have a "next" button at the bottom and have a "before" button at the top (please see attachment.), or b) don't make the before visits not disappear and every time you click next the site only gets longer (to show older visits)
What do you think?