How can i disable all future dates after three days from current date (Today) in AJAX control kit
 <asp:TextBox ID="txtEndDate" runat="server" class="form-control"
      required="This Field is Required" AutoComplete="off"></asp:TextBox>                                                            
        <ajaxToolkit:CalendarExtender ID="CalendarExtender2" 
    runat="server" OnClientDateSelectionChanged="checkProjectEndDate"
 TargetControlID="txtEndDate" Format="dd-MMM-yyyy"></ajaxToolkit:CalendarExtender>
<script type="text/javascript">
     function checkProjectEndDate(sender, args) {
     if (sender._selectedDate >= new Date()) {
     alert("You can not select a future date than today!");
     sender._selectedDate = new Date();
     sender._textbox.set_Value(sender._selectedDate.format(sender._format))
       }
      }
</script>
Its not allowing to select future date then today but i want something that i can select three day latter from today let me explain i want like user can not select any future dates after three days latter suppose today is 01-11-2019 so my calender's show only 03-11-2019 after 3Nov all date should not be visible
 
    