I have discovered a bug that appears when a RadScheduleView is used with the ScheduleViewStyleSelector to style the appointments and the theme is changed.

Steps to reproduce:

1. Setup a WPF project.
2. Use implicit styles with a theme (e.g. Office_Black).
3. Create a possibility to change the theme on runtime (e.g. to Fluent). (https://docs.telerik.com/devtools/wpf/styling-and-appearance/how-to/styling-apperance-themes-runtime)
4. Create a dialog with a RadScheduleView that uses a custom ScheduleViewStyleSelector as AppointmentStyleSelector. (https://docs.telerik.com/devtools/wpf/controls/radscheduleview/styles-and-templates/appointment-style)
5. Create at least one appointment.
6. Start application.
7. Change theme at runtime.

Result: The "old" appearance of the appointments stays after changing the theme.

Expected behavior: The appearance of the appointments changes according to the new theme.

I have attached a solution with the described behavior and an image of the outcome.

When double click on the right of the ViewDefinition buttons new Appointment dialog is shown

In WeekView, when ShowWeekGroupHeaders is set, templating the GroupHeaders with GroupHeaderContentTemplateSelector lead to a rendering issue (see attached files).

In case I forgot something, here is my GroupHeaderContentTemplateSelector definition : 

    <svcore:GroupHeaderContentTemplateSelector x:Key="_GroupHeaderContentTemplateSelectorKey">
      <svcore:GroupHeaderContentTemplateSelector.HorizontalTemplate>
        <DataTemplate>
          <ContentPresenter MinHeight="16" Margin="4" Content="{Binding FormattedName, Converter={StaticResource UpperCaseStringConverter}}"/>
        </DataTemplate>
      </svcore:GroupHeaderContentTemplateSelector.HorizontalTemplate>
      <svcore:GroupHeaderContentTemplateSelector.VerticalTemplate>
        <DataTemplate>
          <ContentPresenter Margin="4" MinHeight="16" VerticalAlignment="Top" Content="{Binding FormattedName, Converter={StaticResource UpperCaseStringConverter}}">
            <ContentPresenter.LayoutTransform>
              <RotateTransform Angle="-90"/>
            </ContentPresenter.LayoutTransform>
          </ContentPresenter>
        </DataTemplate>
      </svcore:GroupHeaderContentTemplateSelector.VerticalTemplate>
      <svcore:GroupHeaderContentTemplateSelector.HorizontalResourceTemplate>
        <DataTemplate>
          <Border Background="{Binding Name.DBResource.Color, Converter={StaticResource _SharedStringColorToSolidColorBrushConverterKey}}" Height="60" Margin="2">
            <StackPanel Orientation="Vertical" Margin="8">
              <TextBlock Foreground="{Binding Name.DBResource.Color, Converter={StaticResource _SharedBackgroundStringColorToForegroundConverterKey}}" FontSize="16" Margin="0" Text="{Binding Name.DisplayName}" />
              <TextBlock Foreground="{Binding Name.DBResource.Color, Converter={StaticResource _SharedBackgroundStringColorToForegroundConverterKey}}" FontSize="12" Text="{Binding Name.DBResource.Code}" />
            </StackPanel>
          </Border>
        </DataTemplate>
      </svcore:GroupHeaderContentTemplateSelector.HorizontalResourceTemplate>
      <svcore:GroupHeaderContentTemplateSelector.VerticalResourceTemplate>
        <DataTemplate>
          <Border Background="{Binding Name.DBResource.Color, Converter={StaticResource _SharedStringColorToSolidColorBrushConverterKey}}" Width="140" Margin="2">
            <StackPanel Margin="8">
              <TextBlock Foreground="{Binding Name.DBResource.Color, Converter={StaticResource _SharedBackgroundStringColorToForegroundConverterKey}}" FontSize="16" Margin="-2 3 0 5"  Text="{Binding Name.DisplayName}" />
              <TextBlock Foreground="{Binding Name.DBResource.Color, Converter={StaticResource _SharedBackgroundStringColorToForegroundConverterKey}}" FontSize="12" Text="{Binding Name.DBResource.Code}" />
            </StackPanel>
          </Border>
        </DataTemplate>
      </svcore:GroupHeaderContentTemplateSelector.VerticalResourceTemplate>
    </svcore:GroupHeaderContentTemplateSelector>

hi,
I have use telerik scheduler for wpf platforms and in timelineview if I add timeslots in 11:00 to 3:00 pm then its shows in scheduler from 11:00 to 2:59 but not shows 3:00.
how 3:00 will also appear on the scheduler.

Reproducible in the latest demo.

Create daily recurrence. Select multiple occurrences and drag them. For the first time they will be dragged. Then select exceptional (this is important!) occurrences and drag them - only the occurrence which was selected first will be dragged.

It happens when the DefaultDialogResult is set to true.

SelectedAppointments should not be read only.

The appointment objects that have been cleared from the appointment source stay alive.