JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.10.1/themes/base/jquery-ui.css">
<script src="//ajax.googleapis.com/ajax/libs/jqueryui/1.10.2/jquery-ui.min.js"></script>
<form action="http://localhost/autogrupe/autonuoma/vw-golf_automobiliu-nuoma.html" enctype="multipart/form-data" id="userForm" method="post">
 

  <table border="0">
    <tbody>
     
      <tr class="rsform-block rsform-block-paemimodata">
        <td>Delivery Date (*)</td>
        <td><input type="text" class="datepicker rsform-input-box hasDatepicker" id="paemimodata" name="form[paemimodata]" size="20" value="2013-05-15">
    
          
        <td></td>
      </tr>
      <tr class="rsform-block rsform-block-paemimolaikas alt">
        <td>Time (Hours) (*)</td>
        <td><select class="rsform-select-box" id="paemimolaikas" name="form[paemimolaikas][]">
            <option value="01">01</option>
            <option value="02">02</option>
            <option value="03">03</option>
            <option value="04">04</option>
            <option value="05">05</option>
            <option value="06">06</option>
            <option value="07">07</option>
            <option value="08">08</option>
            <option value="09">09</option>
            <option value="10">10</option>
            <option value="11">11</option>
            <option value="12">12</option>
            <option value="13">13</option>
            <option value="14">14</option>
            <option value="15">15</option>
            <option value="16">16</option>
            <option value="17">17</option>
            <option value="18">18</option>
            <option value="19">19</option>
            <option value="20">20</option>
            <option value="21">21</option>
            <option value="22">22</option>
            <option value="23">23</option>
            <option value="24">24</option>
          </select>
</td>
        <td></td>
      </tr>
      <tr class="rsform-block...

JavaScript

jQuery(function ($) {
	
function coundays () {
	

var starter = $('#paemimodata').val();

var starterhour = $('#paemimolaikas').val();
var startermin = $('#paemimolaikasmin').val();


var ender =  $('#grazinimodata').val();

var enderhour = $('#grazinimolaikas').val();
var endermin = $('#grazinimolaikasmin').val();

var fullstarter = starter + ' ' +  starterhour + ':' + startermin + ':00';

var fullender = ender + ' ' + enderhour + ':' + endermin + ':00';
alert(fullender);
    var start = new Date(fullstarter);
    var end = new Date(fullender);
var diff = new Date(end - start);
var days = diff/1000/60/60/24;
debugger


alert(days);

};
  
    
 coundays ();
	
	
   $('#userForm').on('change', function() {
	    coundays ();

  });
  

 
	


});