JSFiddle - React, Tailwind, and code Playground

HTML

<input type="file" id="P7_FILEBROWSER"></input>
<input type="text" display="none" id="P7_FILEDATE"></input>

JavaScript

var fileSelect = function(item)
{
    var file   = item.files[0];
    var l_date = new Date();
    l_date=file.lastModifiedDate;
    $('#P7_FILEDATE').val(l_date.getFullYear()+'.'+(1+l_date.getMonth())+'.'+l_date.getDate()+' '+ l_date.getHours()+':'+l_date.getMinutes()+':'+l_date.getSeconds());   
}    
$('#P7_FILEBROWSER').on('change',function(){fileSelect(this);})



//$('#P7_FILEDATE').val('XX');

/*    
    var l_date = new Date(); 
    
    alert('2');
    
    l_date = l_file.lastModifiedDate;

    alert('3');    
    
//    var l_dateString =l_date.getFullYear()+'.'+(1+l_date.getMonth())+'.'+l_date.getDate();
    
    alert(l_date);
    
    //$('#P7_FILEDATE').val(l_dateString);
*/