No problem! Go to the bottom of the wellness report and edit the From: and To: fields as shown in the image and click the "Update" button:

An eagle eye may notice that there are only entries from May 4th to May 8th in this illustration, even though the requested date range starts on May 2nd. The reason for this is that there is no data on May 2nd or 3rd. The athlete in this example did not submit wellness reports on those days, although surely she should have. If you discover blank spaces like this in your reports, it is not because the app is broken, it is because your athlete didn't submit information during that time period.