Use REST in JSOM

get date length in javascript

var d = new Date();
// var month = d.getMonth() + 1;
//var day = d.getDate();

var month = '';
var day = '';
month = d.getMonth() + 1;
day = d.getDate();
var todaysDay =  (day < 10 ? "0" : "") + day ;
var runningMonth = (month < 10 ? "0" : "") + month ;
   
$(document).ready(function () {
 //  SP.SOD.executeOrDelayUntilScriptLoaded(testfunction());
  SP.SOD.executeFunc('sp.js', 'SP.ClientContext', testfunction());
});
function testfunction() {
 $.ajax({

        url: _spPageContextInfo.webAbsoluteUrl + "/_api/web/lists/GetByTitle('EmployeeBirthDetails')/Items?$select=Name,GradeCode,EmpNo,Designation,LocationDesc&$filter=CalMonth eq '"+runningMonth +"' and CalDay eq '" + todaysDay + "' &$orderby=GradeCode asc",      

        type: "GET",
        headers: { "accept": "application/json;odata=verbose" },
        success: successHandlerforBDay,
        error: errorHandlerforBDay
    });
}
function successHandlerforBDay(data) {
var name = 'No Birthday Today', exp = '',  url = '#', html = '', href = '', empimage = '', empdesignation = '', emploc = '';
var empNo='';
if (data.d.results)
{
var object = data.d.results;
if(object.length == 0) // Showing "No Birthday Today" message if object.length == 0.
{
html += '<dd><p class="boxTitle">' + name + '</p></dd>';
}
else
{

for(var i = 0; i < object.length; i++)
{
  empNo = object[i].EmpNo;
 if(empNo.length == 6 ) // Birthday will show for those employee which empNo is equal to 6 digit.
 {
  name =object[i].Name;
  emploc = object[i].LocationDesc;

  html += '<dd class="row"><img src="' + empimage + '" alt="Emp Image" width="80px" height="77px" /><div class="text"><h3>' + name + '</h3><p>Location: ' + emploc + '</p></div></dd>';
 }
}
}
}


// Apply marquee if  there are more than 2 birthday
if(object.length > 2)
{
html = '<marquee direction="up" scrollamount="2"  onMouseOver="this.setAttribute(\'scrollamount\', 0, 0);" OnMouseOut="this.setAttribute(\'scrollamount\',2, 0);">' + html + '</marquee>';
}

   // alert(pictureURL);
 $('.bdayUsers').html(html);
}

function errorHandlerforBDay(args,sender) {
    alert('Failed');
}get date length in javascript