If your document has dates that you want to convert in a specific format, you can adjust the output format in the Options settings.
For example, if the date on your document is formatted yy/mm/dd, but you need the output to be mm/dd/yy.
If your date is a field, right-click on it, then select "Field Format > Date".
If your date is in a table, highlight the column, right-click and select "Column Format in Output > Date".
When you convert the document, the date will show up in the default format, which is YY/MM/DD.
To change this, go to Options > Excel and adjust the format in the Date option of the Cell Format section.
Even though the PDF2XL preview pane may not change, the date in your output should be set up in the format of your choice.