Phpexcel 得到错误的日期

我正在使用phpexcel将excel文档导入网站。我在获取日期格式时遇到问题。

日期格式为 dd.mm.Y，但在获得单元格值后，我得到 samo 随机数 （ float（42391） ）

这是我的代码：

$datum = $objPHPExcel->getActiveSheet()->getCell('A'.$i)->getValue();

这个应该得到日期？

            $file_name = clean_uri($_FILES['excel']['name']);
            $file_name = 'povijest_'.$file_name;
            $folder_s = 'upload_data/excel';
            move_uploaded_file($_FILES['excel']['tmp_name'], '../'.$folder_s.'/'.$file_name);
            $objPHPExcel = PHPExcel_IOFactory::load('../'.$folder_s.'/'.$file_name);
            $allDataInSheet = $objPHPExcel->getActiveSheet()->toArray(null,true,true,true); 
            $highestColumm = $objPHPExcel->getActiveSheet()->getHighestColumn();
            $colNumber = PHPExcel_Cell::columnIndexFromString($highestColumm);
            $arrayCount = count($allDataInSheet); 
for($i=4;$i<=$arrayCount;$i++){
                    $datum = $objPHPExcel->getActiveSheet()->getCell('A'.$i)->getValue();
                    $prva = $objPHPExcel->getActiveSheet()->getCell('C'.$i)->getValue();
                    $zadnja = $objPHPExcel->getActiveSheet()->getCell('D'.$i)->getValue();
                    $najvisa = $objPHPExcel->getActiveSheet()->getCell('E'.$i)->getValue();
                    $najniza = $objPHPExcel->getActiveSheet()->getCell('F'.$i)->getValue();
                    $prosjecna = $objPHPExcel->getActiveSheet()->getCell('G'.$i)->getValue();
                    $promjena = $objPHPExcel->getActiveSheet()->getCell('H'.$i)->getValue();
                    $broj_transakcija = $objPHPExcel->getActiveSheet()->getCell('I'.$i)->getValue();
                    $kolicina = $objPHPExcel->getActiveSheet()->getCell('J'.$i)->getValue();
                    $promet = $objPHPExcel->getActiveSheet()->getCell('K'.$i)->getValue();  
                    var_dump($datum); 
                    exit;