amigos hasta el momento llevo esto
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8" />
<title>jQuery UI Autocomplete - Multiple values</title>
<link rel="stylesheet" href="http://code.jquery.com/ui/1.9.0/themes/base/jquery-ui.css" />
<script src="http://code.jquery.com/jquery-1.8.2.js"></script>
<script src="http://code.jquery.com/ui/1.9.0/jquery-ui.js"></script>
<link rel="stylesheet" href="/resources/demos/style.css" />
<script>
$(document).ready(function(){
$( "#datepicker" ).datepicker();
$("#datepicker").click(function(){
var fecha=this.value;
$("#datepicker").val(fecha+",")
});
$("#tags").keyup(function(){
var escribir=this.value;
$("#tags").val(escribir+",")
//alert(escribir);
});
});
</script>
</head>
<body>
<div class="ui-widget">
<label for="tags">Tag programming languages: </label>
<input id="tags" size="50" />
</div>
<p>Date 1: <input type="text" id="datepicker" /></p>
<p>Date 2: <input type="text" id="datepicker2" /></p>
</body>
</html>