Weekly distance over the last month showing wrong distance for one week only! (Read 28 times)

Not a big deal, but I am curious why this is happening.

The weekly distance over the last month bar graph that is on my summary page will occasionally show the wrong distance for a week. Currently, the week of 5/15 is showing only three miles, when I actually ran 11 or so that week. I can tell by the color coding, that it is also only showing the last run of the week (on a Saturday).

I guessing because it is always interpreting a "month" as 30 days (or possibly 28, depending on my ability to do math), rather than as the last four weeks starting on my first day of week as set in my settings (which is how I would interpret a month for this purpose)?