The GetOccurrencesWithoutExceptionsFromDateTimeRange should return the occurrences of a recurring appointment, without the exceptions (modified or deleted occurrences). However, now the method returns modified occurrences and skips only the deleted ones. The method should skip also the modified occurrences.  

To work this around, exclude the exceptions using their state property:

var occurrencesWithoutExceptions = appointment.GetOccurrencesWithoutExceptionsFromDateTimeRange(appointment.Start, DateTime.Now.AddDays(130)).Where(o => o.State != RecurrenceState.Exception);

In AgendaView, you can see the start, end, and subject of each appointment. When All Day event is set to one appointment, its start and end time is not changed. The text can be changed to All Day Event.

The AppointmentItem element has a default value of Top for the VerticalContentAlignment property for the Windows 11 theme. In other themes, this property has a default value of Stretch.

To change it, create a Style with TargetType="AppointmentItem" and base it on the default AppointmentItemBaseStyle Style. On the newly created Style, set the VerticalContentAlignment property to Stretch (it is currently Top in the Windows11 theme). After that, change the default OrientedAppointmentItemStyleSelector so that each Style for its properties is based on the new Style, rather than the default one (AppointmentItemBaseStyle). Finally, set the custom OrientedAppointmentItemStyleSelector to the AppointmentStyleSelector property of RadScheduleView.

The following code snippet shows this suggestion's implementation:

xmlns:scheduleView="http://schemas.telerik.com/2008/xaml/presentation"

<Style x:Key="CustomAppointmentItemStyle" TargetType="scheduleView:AppointmentItem" BasedOn="{StaticResource AppointmentItemBaseStyle}">
    <Setter Property="VerticalContentAlignment" Value="Stretch"/>
</Style>
<scheduleView:OrientedAppointmentItemStyleSelector x:Key="CustomAppointmentItemStyleSelector">
    <scheduleView:OrientedAppointmentItemStyleSelector.AgendaViewStyle>
        <Style TargetType="scheduleView:AppointmentItem" BasedOn="{StaticResource CustomAppointmentItemStyle}">
            <Setter Property="Margin" Value="3 0 3 3"/>
        </Style>
    </scheduleView:OrientedAppointmentItemStyleSelector.AgendaViewStyle>
    <scheduleView:OrientedAppointmentItemStyleSelector.MonthViewStyle>
        <Style TargetType="scheduleView:AppointmentItem" BasedOn="{StaticResource CustomAppointmentItemStyle}">
            <Setter Property="Margin" Value="2 3 1 0"/>
        </Style>
    </scheduleView:OrientedAppointmentItemStyleSelector.MonthViewStyle>
    <scheduleView:OrientedAppointmentItemStyleSelector.HorizontalStyle>
        <Style TargetType="scheduleView:AppointmentItem" BasedOn="{StaticResource CustomAppointmentItemStyle}"/>
    </scheduleView:OrientedAppointmentItemStyleSelector.HorizontalStyle>
    <scheduleView:OrientedAppointmentItemStyleSelector.VerticalStyle>
        <Style TargetType="scheduleView:AppointmentItem" BasedOn="{StaticResource CustomAppointmentItemStyle}">
            <Setter Property="Margin" Value="1"/>
            <Setter Property="ResizeCursor" Value="SizeNS"/>
            <Setter Property="Template" Value="{StaticResource AppointmentItemVerticalControlTemplate}"/>
        </Style>
    </scheduleView:OrientedAppointmentItemStyleSelector.VerticalStyle>
</scheduleView:OrientedAppointmentItemStyleSelector>
<Style TargetType="scheduleView:RadScheduleView" BasedOn="{StaticResource RadScheduleViewStyle}">
    <Setter Property="AppointmentStyleSelector" Value="{StaticResource CustomAppointmentItemStyleSelector}"/>
</Style>

Issues when using IsGroupHeadersVirtualizationEnabled=true in timeline mode with different-sized resources:

In the scenario where the Fluent theme is applied and the MonthViewDefinition'sAllowCustomAppointmentSize property is set to True, appointments with different heights may overlap the expand/collapse RadToggleButton when collapsed.

To work this around, extract the default GroupHeaderStyleSelector for the Fluent theme. Then, extract the Style with x:Key="MonthViewBottomLevelWeekGroupStyle" and modify the Padding property's value. Set this Style to the MonthViewBottomLevelWeekGroupStyle property of the extracted OrientedGroupHeaderStyleSelector (default GroupHeaderStyleSelector). Finally, set an instance of the modified style selector to the GroupHeaderStyleSelector property of RadScheduleView.

The resized Appointments is not present in the DragDropState.

This only happens when editing existing Appointment.

For example, in DayViewDefinition, while dragging an appointment close to the Day header.

Available in the 2016 Q1 Release.

Available in the 2016 R2 release.