Additional borders appear in AgendaView when the Date column is sorted. This behavior is observed in the following themes:

• VisualStudio2012Light
• Office2019Light
• Office2019Gray
• Office2019Dark
• Office2013Dark (missing border)
• Office2013Light (missing border)
• TelerikMetro (missing border)
• TelerikMetroBlue (missing border)
• TelerikMetroTouch (missing border)
• Office2010Black (missing border)
• Office2010Silver (missing border)
• Office2010Blue (missing border)
• ControlDefault (missing border)
• Breeze (missing border)
• HighContrastBlack (missing border)
• Office2007 (missing border)

To reproduce:
        Me.RadScheduler1.ActiveViewType = Telerik.WinControls.UI.SchedulerViewType.Timeline
        Dim timelineView As SchedulerTimelineView = Me.RadScheduler1.GetTimelineView()
        Dim currentScaling As SchedulerTimescale = timelineView.GetScaling()
        currentScaling.DisplayedCellsCount = 100

Try to scroll horizontally. Then, change the currentScaling.DisplayedCellsCount  property to 50 and try to scroll again. You will notice a considerable difference.

Workaround: reduce the number of the displayed visual cell elements by the DisplayedCellsCount.

Add the possibility to enable rendering appointments not in the whole cell when their duration is less than the range factor of the view.

This request is to add Working hours range of the view, which will style the cells as working and non working. In addition, add a property ShowWorkingHours while will determine whether non-working hours are visible or not.

Or perhaps for the sake of consistency, we can have API as in the day view:
dayView.RangeFactor = ScaleRange.QuarterHour
dayView.RulerStartScale = 9
dayView.RulerStartScaleMinutes = 30
dayView.RulerEndScale = 14
dayView.RulerEndScaleMinutes = 45

To reproduce:
 public Form1()
 {
     InitializeComponent();

     for (int i = 0; i < 7; i++)
     {
         this.radScheduler1.Appointments.Add(new Appointment(DateTime.Now.AddHours(i),TimeSpan.FromHours(3),"App" + i));
     }
     this.radScheduler1.AutoSizeAppointments = true;
     this.radScheduler1.ActiveViewType = SchedulerViewType.Month;
     SchedulerMonthView monthView = this.radScheduler1.GetMonthView();
    
     monthView.EnableAppointmentsScrolling = true;
 }

Workaround: set the AutoSizeAppointments property to false.

To reproduce:

public Form1()
{
    InitializeComponent();

    this.radScheduler1.ActiveViewType = SchedulerViewType.Day;
    RulerPrimitive ruler = (this.radScheduler1.SchedulerElement.ViewElement as SchedulerDayViewElement).DataAreaElement.Ruler;
    ruler.RangeFactor= ScaleRange.TenMinutes;
}

Workaround:

this.radScheduler1.GetDayView().RangeFactor = ScaleRange.TenMinutes;

To reproduce:

Color[] colors = new Color[]
{
    Color.LightBlue, Color.LightGreen, Color.LightYellow,
    Color.Red, Color.Orange, Color.Pink, Color.Purple, Color.Peru, Color.PowderBlue
};
Random rand = new Random();
for (int i = 0; i < 25; i++)
{
    Resource resource = new Resource();
    resource.Id = new EventId(i);
    resource.Name = i + ".Resource";
    resource.Color = colors[rand.Next(0, colors.Length)];
    this.radScheduler1.Resources.Add(resource);
}

this.radScheduler1.GroupType = GroupType.Resource;
this.radScheduler1.ActiveView.ResourcesPerView = this.radScheduler1.Resources.Count;

for (int i = 0; i < 3; i++)
{
    Appointment a = new Appointment(DateTime.Now.AddHours(i), TimeSpan.FromMinutes(30), "A" + i);
    a.ResourceId = this.radScheduler1.Resources.Last().Id;
    this.radScheduler1.Appointments.Add(a);
}

NOTE: it is also valid for the horizontal scrollbar in Timeline view.

Workaround: use the SetResourceSize to increase the last resource's width a little bit: http://docs.telerik.com/devtools/winforms/scheduler/views/grouping-by-resources

When you subscribe to the AppointmentMoved or AppointmentDropped event of RadScheduler, the DataItem property of the appointment in the event args is always null.

1. Create a new project with RadScheduler.
2. Handle the AppointmentFormatting event and change appointment border color.
3. Run the project and add an appointment.

Steps to follow:
1. Select cells from 10:00pm (today) to 01:00am (next day).
2. Right click -> New Appointment
3. The Edit Appointment Dialog opens and the End Time is set to 23:59:59 instead of 01:00:00

The occurrences and the navigation arrows are not displayed correctly when using YearlyRecurrence with the "First Monday of January" rule. The issue also appears with similar rule types.

Check out the Weekly calendar style in Outlook

Resolution: 
In Q2 2014 we introduced new feature: WeeklyCalendarPrintStyle. More information you can find in our help: http://www.telerik.com/help/winforms/scheduler-print-support-schedulerprintstyle.html, section WeeklyCalendarStyle

Check out the Outlook vertical scrolling abilities in MonthView

To reproduce:  

1.Change the first day of week to Monday:

            SchedulerMonthView view = new SchedulerMonthView();
            CultureInfo ci = new CultureInfo("en-US");
 
            ci.DateTimeFormat.FirstDayOfWeek = DayOfWeek.Monday;
            view.CurrentCulture = ci;
            this.radScheduler1.ActiveView = view;
2. Create an appointment with a recurrence rule illustrated in the attached screenshot. Imagine that today is Wednesday and the recurrence rule starts on Monday from the same week.
As a result, you will notice that the WeeklyRecurrenceRule.FirstDayOfWeek is not set and the appointment occurs on the wrong Sundays. Refer to the attached screenshot. 

Workaround:

        private void radScheduler1_AppointmentAdded(object sender, AppointmentAddedEventArgs e)
        {
            if (e.Appointment.RecurrenceRule != null)
            {
                WeeklyRecurrenceRule r = e.Appointment.RecurrenceRule as WeeklyRecurrenceRule;
                r.FirstDayOfWeek = DayOfWeek.Monday;
            }
        }

How to reproduce: check the attached (video radscheduler-selection-incorrect.gif)
 public RadForm1()
 {
     InitializeComponent();

     Appointment appointment = new Appointment(DateTime.Today.AddHours(13), TimeSpan.FromHours(1), "Test Appointment");
     this.radScheduler1.Appointments.Add(appointment);

     for (int i = 0; i < 25; i++)
     {
         appointment = new Appointment(DateTime.Today.AddHours(24), TimeSpan.FromHours(1), "AllDay: " + i);
         appointment.AllDay = true;
         this.radScheduler1.Appointments.Add(appointment);
     }
     this.radScheduler1.AllowAppointmentsMultiSelect = true;
 }

Workaround: create a custom input behavior

this.radScheduler1.SchedulerInputBehavior = new CustomSchedulerInputBehavior(this.radScheduler1);

public class CustomSchedulerInputBehavior : SchedulerInputBehavior
{
    public CustomSchedulerInputBehavior(RadScheduler scheduler) 
        : base(scheduler)
    {
    }

    public override bool HandleMouseWheel(MouseEventArgs args)
    {
        if (!this.Scheduler.AllowMouseWheelSupport)
            return false;

        bool scrolled = false;

        if (this.Scheduler.SelectionBehavior.IsAllDayAreaSelection || this.IsLastSelectedAppointmentAllDay(this.Scheduler.SelectionBehavior.SelectedAppointments))
        {
            if (this.Scheduler.GroupType == GroupType.Resource)
            {
                SchedulerDayViewGroupedByResourceElement grouped = this.Scheduler.ViewElement as SchedulerDayViewGroupedByResourceElement;
                IList<SchedulerDayViewElement> childViews = grouped != null ? grouped.GetChildViewElements() : null;
                if (childViews != null && childViews.Count > 0)
                {
                    RadScrollBarElement scroll = childViews[childViews.Count - 1].AllDayHeaderElement.ScrollBar;
                    if (scroll.Visibility != ElementVisibility.Collapsed)
                    {
                        int newValue = scroll.Value - childViews[childViews.Count - 1].AllDayHeaderElement.HeaderHeight * Math.Sign(args.Delta);
                        newValue = Math.Max(Math.Min(newValue, scroll.Maximum - scroll.LargeChange + 1), scroll.Minimum);
                        scroll.Value = newValue;
                        scrolled = true;
                    }
                }
            }
            else
            {
                SchedulerDayViewElement dayView = this.Scheduler.ViewElement as SchedulerDayViewElement;
                RadScrollBarElement scroll = dayView != null ? dayView.AllDayHeaderElement.ScrollBar : null;

                if (scroll != null && scroll.Visibility != ElementVisibility.Collapsed)
                {
                    int newValue = scroll.Value - dayView.AllDayHeaderElement.HeaderHeight * Math.Sign(args.Delta);
                    newValue = Math.Max(Math.Min(newValue, scroll.Maximum - scroll.LargeChange + 1), scroll.Minimum);
                    scroll.Value = newValue;
                    scrolled = true;
                }
            }
        }

        if (scrolled)
        {
            return false;
        }

        if (args.Delta > 0)
        {
            this.Scheduler.ViewElement.Scroll(true);
        }
        else
        {
            this.Scheduler.ViewElement.Scroll(false);
        }
        return false;
    }

    private bool IsLastSelectedAppointmentAllDay(ReadOnlyCollection<IEvent> selectedAppointments)
    {
        if (selectedAppointments.Count > 0)
        {
            return selectedAppointments[selectedAppointments.Count - 1].AllDay;
        }

        return false;
    }

}

Workaround:

Sub New()

    InitializeComponent()
     
    Me.RadScheduler1.ActiveViewType = UI.SchedulerViewType.Week
    AddHandler Me.RadSchedulerNavigator1.SchedulerNavigatorElement.ShowWeekendCheckBox.ToggleStateChanged, AddressOf ToggleStateChanged
End Sub

Private Sub ToggleStateChanged(sender As Object, args As UI.StateChangedEventArgs) 
    Me.RadScheduler1.SchedulerElement.RefreshViewElement()
End Sub

Please refer to the attached gif file and sample project.

Workaround: remove the database restrictions and validate the data in the edit dialog before submitting the new appointment data.

Please refer to the attached screenshot from Outlook.