public partial class Form1 : Form
    {
        public class VM
        {
            public string Text
            {
                get; set;
            }
            public DateTime Start
            {
                get; set;
            }
            public DateTime End
            {
                get; set;
            }
        }

        public Form1()
        {
            InitializeComponent();

            var ViewModel = new VM[]
            {
                new VM()
                {
                    Text = "CrashTest",
                    Start = new DateTime(2021, 11, 3, 10, 0, 0),
                    End = new DateTime( 2021, 11, 3, 23, 0, 0 )  //crash
                    //End = new DateTime( 2021, 11, 3, 22, 0, 0 )  //No crash
                },
            };

            radGanttView1.GanttViewElement.GraphicalViewElement.OnePixelTime = new TimeSpan( 0, 1, 0 );
            radGanttView1.GanttViewElement.GraphicalViewElement.TimelineStart = ViewModel.Min( T => T.Start );
            radGanttView1.GanttViewElement.GraphicalViewElement.TimelineEnd = ViewModel.Max( T => T.End );
            radGanttView1.GanttViewElement.GraphicalViewElement.TimelineRange = TimeRange.Day;

            radGanttView1.GanttViewElement.ChildMember = "Text";
            radGanttView1.GanttViewElement.TitleMember = "Text";
            radGanttView1.GanttViewElement.StartMember = "Start";
            radGanttView1.GanttViewElement.EndMember = "End";

            radGanttView1.DataSource = ViewModel;
        }
    }

  radGanttView1.GanttViewElement.GraphicalViewElement.TimelineEnd = ViewModel.Max( T => T.End.AddHours(1));