When the IsGroupHeadersVirtualizationEnabled property is set to True, changing the VisibleDays of the active view definition from a higher value to a smaller one causes appointments to not be displayed.

To work this around, call the Measure method of RadScheduleView when the VisibleDays property changes:

public class RadScheduleViewExtensions
{
    public static int GetVisibleDays(DependencyObject obj)
    {
        return (int)obj.GetValue(VisibleDaysProperty);
    }

    public static void SetVisibleDays(DependencyObject obj, int value)
    {
        obj.SetValue(VisibleDaysProperty, value);
    }

    public static readonly DependencyProperty VisibleDaysProperty =
        DependencyProperty.RegisterAttached("VisibleDays", typeof(int), typeof(RadScheduleViewExtensions), new PropertyMetadata(0, OnVisibleDaysChanged));

    private static void OnVisibleDaysChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        RadScheduleView scheduleView = (RadScheduleView)d;

        if (scheduleView.IsLoaded)
        {
            scheduleView.Measure(Size.Empty);
                
            Dispatcher.CurrentDispatcher.BeginInvoke(new Action(() =>
            {
                Size renderSize = scheduleView.RenderSize;
                scheduleView.Measure(renderSize);
            }), (DispatcherPriority)3);
        }
    }
}

<telerik:RadScheduleView x:Name="scheduleView"
                         AppointmentsSource="{Binding Appointments}"
                         local:RadScheduleViewExtensions.VisibleDays="{Binding MyPropertyForVisibleDays}"
                         IsGroupHeadersVirtualizationEnabled="True">
    <telerik:RadScheduleView.ViewDefinitions>
        <telerik:DayViewDefinition VisibleDays="{Binding MyPropertyForVisibleDays, Mode=TwoWay}" />
    </telerik:RadScheduleView.ViewDefinitions>
</telerik:RadScheduleView>

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);

Drag and drop is not working properly for RadScheduleView WPF running inside WindowsFormsHost, in a WPF Browser Application. When you drag an appointment, it drops it in another location. 

The hierarchy of child controls is as follows:
•	WPF XAML Browser App page, containing a WinFormsHost  (WPF)
  o	WInFormsControl containing a ElementHost control (WinForms)
   	WPFUserControl containing RadScheduleView (WPF)
Please see the attached sample project that demonstrates this issue. I would like to make the whole application WPF, however the parents of the WPFUserControl are an existing application where we want to include the RadScheduleView.

*  SnapAppointments should cause appointments to snap to tick marks, as it does now.
 *  By default, SnapAppointments should not prevent the start/end time from falling outside the visible time range. (Or at least it should consistently prevent or allow this.)
 *  There should be another bool property that prevents/allows the start/end time to be outside the bounds of the visible time range.
http://admin.telerik.com/?Context=Support&Control=%7e%2fUserControls%2fSupport%2fThreadReply.ascx&ST=425043&SM=0

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

When creating an recurrent appointment on the 31st of the month Outlook gives the user a warning: "Some months have fewer than 31 days. For these months, the occurrence will fall on the last day of the month."  And as the message indicates, the event occurrences would start on the last day of the month when the 31st does not exist. 

This will set the occurrences at the end of each month regardless of the length of the month.

Implement automatic scroll when selecting timeSlots with mouse, maybe also when dragging/resizing app.

When have several day events and appointments built for the day, changing  the view definition by week  to  day view definition layout broken.

When using the CreateAppointment command from a context menu, right clicking on a Recurrent appointment and the created appointment takes the Start/End time of the parent appointment not of the ocurrence and also the created appointment is recurrent.

All day reccurent appointments are not shown in DayView and in the last shown day of WeekView. If Start/End time is not set it is working as expected.

There are some double lines between the groups in the ScheduleView.
Also, the lines of the headers in the MonthView are displaced.