I've checked the file that you provided, looking at your date issue.
The format that you're using for those dates in your spreadsheet is a locale-aware date format, flagged by MS Excel with an asterisk (*) if you look at the cell format
This means (quoting from Excel's notes on the format mask display):
Date formats that begin with an asterisk (*) respond to changes in regional date and time settings that are specified for the Operating System.
Because PHPExcel is not locale-aware, but does recognise the format mask as a date value, it uses a generic formatting.
Running the following code
var_dump($objPHPExcel->getActiveSheet()->getCell('I5')->getValue());
var_dump(PHPExcel_Shared_Date::isDateTime($objPHPExcel->getActiveSheet()->getCell('I5')));
var_dump($objPHPExcel->getActiveSheet()->getCell('I5')->getStyle()->getNumberFormat()->getFormatCode());
var_dump($objPHPExcel->getActiveSheet()->getCell('I5')->getFormattedValue());
gives
float(42062)
bool(true)
string(8) "mm-dd-yy"
string(8) "02-27-15"
So (as long as you've removed that setReadDataOnly(true) call from the Reader, call from the Reader, you can still identify date cells as dates, and format them manually, overriding the default locale-formatting
if (PHPExcel_Shared_Date::isDateTime($objPHPExcel->getActiveSheet()->getCell('I5'))) {
$dateTimeObject = PHPExcel_Shared_Date::ExcelToPHPObject($objPHPExcel->getActiveSheet()->getCell('I5')->getValue());
echo $dateTimeObject->format('d-m-Y'), PHP_EOL;
}