The next tab is the monthly log. You can go back to any day you have logs for and plot the chart for that day. If you select more than one day (or the whole month) you can have a graph that shows the average worked time for all those days. Each bar is a day.

This graph is a good way to figure out how many productive hours your day actually has, and which days you get the most interruptions. If you need more detail, you can always go down to the day and hour level by selecting individual days.