jquerydatepicker

HTML

<title>jQuery UI Datepicker - Default functionality</title>
<link rel="stylesheet" href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css" />
<script src="http://code.jquery.com/jquery-1.9.1.js"></script>
<script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script>
<link rel="stylesheet" href="/resources/demos/style.css" />
<script>
    $(function() 
    {
    //$( "#datepicker" ).datepicker();
    //$( "#datepicker" ).datepicker( "option", "firstDay", 6 );
      $('#datepicker').datepicker({
      	firstDay: 6,
        beforeShowDay: function(date) {
            var weekend = date.getDay() == 4 || date.getDay() == 5;
            return [!weekend, weekend ? 'myweekend' : ''];
      	}
    	});    
});    
    
</script>
</head>
<body>
<p>Date: <input type="text" id="datepicker" /></p>
</body>
</html>

CSS

.myweekend span.ui-state-default { color: red; }