JSFiddle - React, Tailwind, and code Playground

HTML

<script src="www.datejs.com/build/date.js"></script>
<script src="http://www.datejs.com/build/date.js" type="text/javascript"></script>
<div class="demo"></div>

JavaScript

var dateStart="31-08-2018";
    var splitSrt = dateStart.split("-");
  	var dateSrt = new Date(splitSrt[2], splitSrt[1] - 1, splitSrt[0]);
    var nBill=10;
    var mthBill=6;
    
  for (var i=1 ; i<=nBill ; i++ ){
      if(i===1){
              srvDay =  new Date(dateSrt.getFullYear(), dateSrt.getMonth(), dateSrt.getDate());
      }else if(i===2){
              newDate = dateSrt.addMonths(mthBill - 1); 
              srvDay =  new Date(newDate.getFullYear(), newDate.getMonth(), newDate.getDate());
              newDate = dateSrt.addMonths(1); 
      }else if(i<=nBill){
              newDate = dateSrt.addMonths(mthBill); 
              srvDay =  new Date(newDate.getFullYear(), newDate.getMonth(), newDate.getDate());
      }
      srvDay= $.datepicker.formatDate('dd-mm-yy', srvDay);
      $(".demo").append("<label>"+srvDay+"</label><br>");
  }