public ActionResult About()
        {
            ViewBag.Message = "Your application description page.";
            CalendarContext db = new CalendarContext();
            DateTime VisibleStart = new DateTime(2017, 01, 22, 06, 00, 00);
            DateTime VisibleEnd = new DateTime(2017, 01, 22, 23, 00, 00);
            var Workers = (from x in db.WorkSchedulers
                           where !((x.PlanEnd <= VisibleStart) || (x.PlanStart >= VisibleEnd))
                           select x).ToList();
            ViewBag.Persons = Workers;
            return View();
        }