Hi Mudassirk7,
Unfortunately there are no server side events attached to the Ajax CalendarExtender like ASP.net Calendar. Ajax CalendarExtender is attached with client side events like OnClientDateSelectionChanged and etc.
So you need to do workaround for achieving the task and for that i have already provided solution to you in my previous reply.
http://www.aspforums.net/Threads/645107/Enabling-only-one-week-in-ajax-calendar-extender/Replies/2#Replies
and you can achieve your requirement with jquery datepicker.
Refer below sample code.
HTML
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<input type="text" id="txtSundays" />
<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.5/themes/base/jquery-ui.css"
type="text/css" media="all" />
<link rel="stylesheet" href="http://static.jquery.com/ui/css/demo-docs-theme/ui.theme.css"
type="text/css" media="all" />
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js" type="text/javascript"></script>
<script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.5/jquery-ui.min.js"
type="text/javascript"></script>
<style type="text/css">
.ui-datepicker-week-end a.ui-state-default
{
color: green;
}
</style>
<script type="text/javascript">
$(function () {
var date = new Date();
$("#txtSundays").datepicker({
autoclose: true,
changeMonth: true,
changeYear: true,
changeDate: true,
minDate: new Date(),
beforeShowDay: function (date) {
return [date.getDay() === 0, ''];
}
});
});
</script>
</div>
</form>
</body>
</html>
Demo