DayRender event is raised while the Calendar control is being rendered, you cannot add a control that can also raise an event, such as LinkButton. You can only add static controls, such as System.Web.UI.LiteralControl, Label, Image, and HyperLink.

Add Calendar Control on to the page:Calendar.aspx:
  1. <asp:Calendar ID="Calendar1" runat="server">
  2. </asp:Calendar>
Add Day Render Event:
  1. protected void Page_Load(object sender, EventArgs e)
  2. {
  3. Calendar1.DayRender += new DayRenderEventHandler(Calendar1_DayRender);
  4. }
  6. void Calendar1_DayRender(object sender, DayRenderEventArgs e)
  7. {
  8. if (e.Day.Date.Day == 8)
  9. {
  10. e.Cell.Controls.Add(new LiteralControl("<br/>Holiday"));
  11. }
  12. }
Output: