Hi,

That is possible, but it can be done on client only and requires some knowledge of javascript. You can process ClientSideEvents.Click to cancel mouse click action, you may process ClientSideEvents.RenderDay to customize appearance of days in calendar, and you also may pass array of dates from server for those client events. Below example will process those events and use listOfDates as array container for [year,month,day] disabled dates passed from server.

<script type="text/javascript">
//array of disabled dates
//line below will be passed from server. Uncomment it for test before server implementation
//var listOfDates = [[2008,5,5],[2008,5,6],[2009,2,7],[2009,2,10]];
function WebCalendarView1_RenderDay(oCalendarView, oEvent, day)
{
 var i = listOfDates ? listOfDates.length : 0;
 while(i-- > 0)
 {
   var item = listOfDates[i];
   if(day.year == item[0] && day.month == item[1] && day.day == item[2])
   {
     day.css += ' grayCss';
     //day.element.style.color = '#C0C0C0';
   }
 }
}
function WebCalendarView1_Click(oCalendarView, oEvent, element)
{
  if(!element) return;
  var css1 = element.className, css2 = element.parentNode.className;
  if(css1.indexOf(' grayCss') >= 0 || css2.indexOf(' grayCss') >= 0)
    oEvent.cancel = true;
  //it is also possible to find actual day from element.id (from digits after _id)
}
</script>

<igsch:WebCalendarView ID="WebCalendarView1" runat="server" WebScheduleInfoID="WebScheduleInfo1" >
  <ClientEvents RenderDay="WebCalendarView1_RenderDay" Click="WebCalendarView1_Click"></ClientEvents>
</igsch:WebCalendarView>

protected void Page_Load(object sender, EventArgs e)
{
 System.Text.StringBuilder dates = new System.Text.StringBuilder();
 dates.Append("<script type=\"text/javascript\">");
 dates.Append("var listOfDates=[");
 //
 DateTime d = DateTime.Now.AddDays(1);
 dates.Append("[").Append(d.Year).Append(",").Append(d.Month).Append(",").Append(d.Day).Append("]");
 //
 d = DateTime.Now.AddDays(3);
 dates.Append(",");
 dates.Append("[").Append(d.Year).Append(",").Append(d.Month).Append(",").Append(d.Day).Append("]");
 //
 d = DateTime.Now.AddDays(4);
 dates.Append(",");
 dates.Append("[").Append(d.Year).Append(",").Append(d.Month).Append(",").Append(d.Day).Append("]");
 //
 dates.Append("];");
 dates.Append("</script>");
 this.Page.RegisterClientScriptBlock("badDates", dates.ToString());
}