The ShowNonworkingHours property specifies whether the non-working hours are shown on the chart. While the Chart.ShowNonworkingHours property is True and Chart.ShowNonworkingUnits property is True, the non-working hours are visible on the chart only if the Chart.NonworkingHours property is set, Chart.UnitScale is exDay ( and Level.Count property is 1 ), exHour, exMinute and exSecond. The NonworkingHours property indicates the non-working hours with in a day. The non-working hours are shown using the NonworkingHoursPattern and the NonworkingHoursColor which defines the pattern and the color, when the base level of the chart displays hours, if the ShowNonworkingUnits property is True ( by default ). 

The following screen shot shows the control's chart when ShowNonworkingHours and ShowNonworkingUnits properties are False:

The following screen shot shows the control's chart when ShowNonworkingHours and ShowNonworkingUnits properties are True ( by default ):