If you use "-" (dash) as the Text property value, the item will be displayed as a menu item separator.
DayPilot<%= Html.DayPilotMenu("menu", new DayPilotMenuConfig {
CssClassPrefix = "menu_",
Items = new DayPilot.Web.Mvc.MenuItemCollection
{
new DayPilot.Web.Mvc.MenuItem { Text = "Open", Action = MenuItemAction.JavaScript, JavaScript = "alert(e.value());"},
new DayPilot.Web.Mvc.MenuItem { Text = "-",
new DayPilot.Web.Mvc.MenuItem { Text = "Delete", Action = MenuItemAction.CallBack, Command = "Delete"}
}
})
%>