Firefox only (Win/Mac/Linux): Firefox extension about:me displays statistics and graphs showing your browsing and downloading history over time, so you can see a more detailed view of when and where you've been spending your time.
Once you've installed the extension, you can simply type about:me into the address bar to see graphs and statistics of your most frequently used sites, downloads and even your browsing history in an hourly format so you can see when you tend to do the most browsing. You can drill down into each site, or each type of download to see even more information about the pages you are visiting the most, as well as the types of files you are downloading. About:me is a free download, works anywhere Firefox does.
about:me [Mozilla Add-ons]