As Validis is an international company, many of the dates within the excel files are formatted for European standards. However, there is a simple way to format the dates to the American standard.
Within the selected excel file, click on the column of the dates you would like to change. Then right-click and select "Format Cells".
First, select on "Date" from the Category section. Then select the appropriate MM/DD/YY format from the Type options. Ensure your location is set to "English (United States)".
After all of these have been selected, click on OK.
The dates within the column will now be set to the American standard.