jQuery UI: Date Picker
Date Picker
HTML
<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.18/themes/mint-choc/jquery-ui.css">
<p>Date: <input type="text" class="datepicker"/></p>
<p>Date2: <input type="text" class="datepicker"/></p>
<p>Date3: <input type="text" class="datepicker"/></p>
JavaScript
$(".datepicker").datepicker();
$(document.body).on('change keyup','.datepicker',function(){
alert('updated ' + this.value);
});