Cells formatting can’t change your current date format to new one, which you’ll set in table settings. If you want to have one format for all cells in column, you should set Date format to thic column and then manually set date from calendar to each cell.
Unfortunately it is not possible to convert “Feb. 23, 2017” to “MM-DD-YYYY” format, because date is stored in Data Base as text.
Also, plugin can’t interprete exactly what is “06.07.2018” – it can be the sixth of July or the seventh of June. It depends of format, which you set in table settings.