PHP excel import time format conversion

1、excel After importing in ：excel Time is 2014-5-27 This format , But import php The file is 41986 A string of numbers , terms of settlement ：

function excelTime($days, $time=false){
    
    if(is_numeric($days)){
    
        //based on 1900-1-1
        $jd = GregorianToJD(1, 1, 1970);
        $gregorian = JDToGregorian($jd+intval($days)-25569);
        $myDate = explode('/',$gregorian);
        $myDateStr = str_pad($myDate[2],4,'0', STR_PAD_LEFT)
                ."-".str_pad($myDate[0],2,'0', STR_PAD_LEFT)
                ."-".str_pad($myDate[1],2,'0', STR_PAD_LEFT)
                .($time?" 00:00:00":'');
        return $myDateStr;
    }
    return $days;
}


 Call is direct excelTime($day);$day by excel Read the time value .