ASP.NET includes a built in calendar control 'asp:Calendar' which is an easy way to display a calendar on your page. This is fully customisable in terms of look and feel and you can use this functionality to apply restrictions to the selectable dates. A lot times when building commercial websites the calendar week should only really apply to week days and not weekends. Although you should be checking this in your business logic layers, it is helpful to users if we do not let them submit invalid information. The following shows how you disable the weekend days by 'greying them out' (there is no reason why you could simply hide them altogether). Declare the calendar control:
<asp:Calendar ID="calCollectionDate" runat="server" SelectionMode="Day" WeekendDayStyle-CssClass="disabledDay"></asp:Calendar>
Use Javascript to find the 'disabledDay' items and remove the links:
<script type="text/javascript" language="javascript">
  var disabledDays=getElementsByClassName('disabledDay', '.*', document.getElementById('<%=calCollectionDate.ClientID %>'));
  for(var i=0;i<disabledDays.length;i++)

This script relies on a third party script for 'getElementByClassName' which can be downloaded from