public IActionResult SaveEvent(Event eventModel, List <string> NotificationForUserIds)
        {
            if (ModelState.IsValid)
            {
                eventModel.EndTime = EventHelper.CalculateDate(eventModel.StartTime, eventModel.Duration, eventModel.DurationType);
                _queries.AddEvent(eventModel, NotificationForUserIds);
                return(RedirectToAction("Events"));
            }
            List <User> users = _queries.GetAllUsers();

            ViewBag.AllUsers = users;
            return(View("CreateEvent"));
        }