When you use dates in your CSV import file, you need to make sure the format is correct.
It needs to be YYYY-MM-DD hh:mm:ss
If you work with MS Excel, make sure you change the format of the date columns BEFORE entering the dates, because Excel converts the format automatically.
Also, Excel does not keep the modifications you might apply to columns in your file. So if you change the date formats, save and close the file, upon reopening the file, Excel would have not kept your format, and would automatically convert teh dates again.
Once you have setup the correct format, entered the dates, save the file and upload it onto Store Commander Import window for the correct date format to be used during the import process.