PHP - Spreadsheet_Excel_Reader campo fecha

$data = new Spreadsheet_Excel_Reader();

    $data->setOutputEncoding('CP1251');

    $data->read("../temp/excelF.xls");

    for ($i = 1; $i <= $data->sheets[0]['numRows']; $i++) {

        echo "fecha: ".$dia = @$data->sheets[0]['cells'][$i][2];  //i=línea; 2=columna

$dia =  $sheet->getCell("B".$row)->getValue();

                        $excelTS = $dia + +0.193056;

                        $unixDT = ($excelTS - 25569) * 86400;

                        $gmtDate= gmdate("d-m-Y H:i:s", $unixDT);

                        $mDate = new DateTime($gmtDate);

                        $dia = $mDate->format("d/m/Y");