Code

if (e.Element == CustomDrawElements.ResourceViewCell)
            {
                if (_pointedDate > DateTime.Now)
                {

                    TimeSpan segment = TimeSpan.FromHours(1);
                    DateTime cellStart = e.Date + e.StartTime;
                    DateTime cellEnd = e.Date + e.EndTime;
                    Rectangle bounds = e.Bounds;

                    string _resName = string.Empty;
                    if (_res != null) //comes from dragover
                        _resName = _res.Name;

                    bounds.Width -= 1;
                    bounds.Height -= 1;
                    if (cellStart <= _pointedDate && _pointedDate < cellEnd)
                    {
                        e.Graphics.FillRectangle(new SolidBrush(Color.FromArgb(190, 250, 190)), bounds);
                        bounds.Y += 1;
                        bounds.Height -= 1;

                        string interval = _resName + " " + cellStart.ToString("HH:mm");
                        e.Graphics.DrawString(interval, Font, Brushes.Gray, bounds.Left + 2, bounds.Top + 2);
                    }

                }
            }