Dashboard display of "last 30 days"

Idea: make the month display show the last thirty days rather than or in addition to the calendar month.

At the beginning of the month, this view doesn't really show anything useful. It's April 1st but I can't display my "time spent" for any time earlier than yesterday unless I choose "this year" which is too slow on my computer. By contrast, yesterday I could see a lot of information in the "this month" view.

I think this should change because it doesn't make sense that the amount of info you see in "this month" should be so variable based just on whether the date is a low or high number.