Fix FetchNewAppointments logic to return appointments for all visible dates instead for only one month

Controls/Input/Input.UWP/Calendar/View/RadCalendar.cs

@@ -3069,20 +3069,33 @@ namespace Telerik.UI.Xaml.Controls.Input
                     this.defaultHighlightedCellStyle = (CalendarCellStyle)RadCalendar.MultiDayViewResources[DefaultHighlightedCellStyleName];
                 }
             }
-        }
-
-        private void FetchNewAppointments()
-        {
-            if (this.AppointmentSource != null && this.IsTemplateApplied)
-            {
-                DateTime startDate = GetFirstDayofMonth(this.DisplayDate, this.currentCulture.Calendar);
-                ObservableCollection<IAppointment> fetchedAppointments = this.AppointmentSource.FetchData(startDate, startDate.Month == DateTime.MaxValue.Month && startDate.Year == DateTime.MaxValue.Year ? startDate : startDate.AddMonths(1));
-                this.AppointmentSource.AllAppointments.Clear();
-                foreach (IAppointment app in fetchedAppointments)
-                {
-                    this.AppointmentSource.AllAppointments.Add(app);
-                }
-            }
+        }
+
+        private void FetchNewAppointments()
+        {
+            if (this.AppointmentSource != null)
+            {
+                var rowCount = this.model.RowCount;
+                int columnCount;
+                if (this.DisplayMode == CalendarDisplayMode.MultiDayView)
+                {
+                    columnCount = 3 * this.MultiDayViewSettings.VisibleDays;
+                }
+                else
+                {
+                    columnCount = this.model.ColumnCount;
+                }
+
+                DateTime startDate = this.model.GetFirstDateToRenderForDisplayMode(this.DisplayDate, this.DisplayMode);
+                DateTime endDate = startDate.AddDays(rowCount * columnCount);
+
+                ObservableCollection<IAppointment> fetchedAppointments = this.AppointmentSource.FetchData(startDate, startDate.Month == DateTime.MaxValue.Month && startDate.Year == DateTime.MaxValue.Year ? startDate : endDate);
+                this.AppointmentSource.AllAppointments.Clear();
+                foreach (IAppointment app in fetchedAppointments)
+                {
+                    this.AppointmentSource.AllAppointments.Add(app);
+                }
+            }
         }
 
         private void AddLayer(CalendarLayer layer, Panel parent)