To reproduce:
public Form1()
{
    InitializeComponent(); 
    for (int i = 0; i < 10; i++)
    {
        Appointment appointment = new Appointment(DateTime.Now.AddHours(i),
            TimeSpan.FromMinutes(30), "Summary", "Description");
        appointment.StatusId = 2;
        appointment.BackgroundId = 6;
        this.radScheduler1.Appointments.Add(appointment);
    }

    this.radScheduler1.ActiveViewType = SchedulerViewType.Day;
    SchedulerDayView dayView = this.radScheduler1.GetDayView();
    dayView.RangeFactor = ScaleRange.FiveMinutes;
    dayView.RulerStartScale = DateTime.Now.Hour - 1;
    this.radScheduler1.EnableExactTimeRendering = true;
}