JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://cdn.kendostatic.com/2012.1.322/styles/kendo.common.min.css">
<link rel="stylesheet" href="http://cdn.kendostatic.com/2012.1.322/styles/kendo.default.min.css">
<script src="http://cdn.kendostatic.com/2012.1.515/js/kendo.all.min.js"></script>
<div id="grid"></div>

CSS

.selected{
  background: red;
  color: white;    
}

JavaScript

var dataSource = new kendo.data.DataSource({
    data: [{
        Qty: 10,
        Amt: 20,
        Total: 200,
        start:'11/12/2018',
        end:'11/19/2018',
        Duration:''}],
    schema: {
        model: {
            //id: "ID",
            fields: {
                Qty: {
                    type: "number"
                },
                Amt: {
                    type: "number"
                },
                Total: {
                    type: "number"
                },start: {
                    type: "date"
                },
                end: {
                    type: "date"
                }
            }
        }
    },
    pageSize: 4 
});

$("#grid").kendoGrid({
    dataSource: dataSource,
    columns: ["Qty", "Amt", { field: "start", title:"start", width: "100px",  format: "{0:MM/dd/yyyy}" },
    
    { field: "end", title:"end", width: "100px", format: "{0:MM/dd/yyyy}"}, {title:"Duration", width: "100px",template: "#= calculateDates(start, end) #Days"},  
    {
        field: "Total",
        editor: function(cont, options) {
        alert('aa');
            $("<span>" + options.model.Total + "</span>").appendTo(cont);
        }}],
    editable: true,
    save: function(data) {
         if (data.values.Qty) {
          alert('aa');
            var test = data.model.set("Total", data.values.Qty * data.model.Amt);
            
            
            var diff = Math.round((data.values.start - data.model.end)/1000/60/60/24); 
            var testone =data.model.set("Duration", diff);
            
           /*     var test = data.model.set("Total", data.model.Qty * data.values.Amt);
             alert(data.values.start );
              alert(data.values.end );
             var diff = Math.round((data.values.start - data.values.end)/1000/60/60/24); 
               alert(diff);
            var testone =data.model.set("Duration", diff); */
       
            
            
        }
        else {
         alert('a');
          ...