The Add method magnifies a date, and retrieves the InsideZoom object that may be used to customize the zoomed date. In other words, you can use the Add method to programmatically zoom, magnify, or change the visual appearance for a specified time unit. The control fires the InsideZoom event once a new date gets magnified. The Add method retrieves nothing, if the AllowInsideZoom property is False. An inside zoom unit may display a different label, background and so on. The DefaultInsideZoomFormat retrieves an InsideZoomFormat object that customizes the dates being magnified. Use the Width property to specify the width of the time scale unit being changed. Once a new date is added to InsideZooms property, the DefaultWidth property specifies the default width being used. 

The following VB sample shows how can I change the background color for a time unit, in the chart area:

With G2antt1
	.BeginUpdate 
	With .Chart
		.LevelCount = 2
		.FirstVisibleDate = #1/1/2008#
		.AllowInsideZoom = True
		.AllowResizeInsideZoom = False
		.InsideZoomOnDblClick = False
		.DefaultInsideZoomFormat.BackColorChart = 255
		With .InsideZooms
			.SplitBaseLevel = False
			.DefaultWidth = 18
			.Add(#1/4/2008#).AllowInsideFormat = False
		End With
	End With
	.EndUpdate 
End With

The following VB.NET sample shows how can I change the background color for a time unit, in the chart area:

With AxG2antt1
	.BeginUpdate 
	With .Chart
		.LevelCount = 2
		.FirstVisibleDate = #1/1/2008#
		.AllowInsideZoom = True
		.AllowResizeInsideZoom = False
		.InsideZoomOnDblClick = False
		.DefaultInsideZoomFormat.BackColorChart = 255
		With .InsideZooms
			.SplitBaseLevel = False
			.DefaultWidth = 18
			.Add(#1/4/2008#).AllowInsideFormat = False
		End With
	End With
	.EndUpdate 
End With

The following C++ sample shows how can I change the background color for a time unit, in the chart area:

/*
	Copy and paste the following directives to your header file as
	it defines the namespace 'EXG2ANTTLib' for the library: 'ExG2antt 1.0 Control Library'

	#import <ExG2antt.dll>
	using namespace EXG2ANTTLib;
*/
EXG2ANTTLib::IG2anttPtr spG2antt1 = GetDlgItem(IDC_G2ANTT1)->GetControlUnknown();
spG2antt1->BeginUpdate();
EXG2ANTTLib::IChartPtr var_Chart = spG2antt1->GetChart();
	var_Chart->PutLevelCount(2);
	var_Chart->PutFirstVisibleDate("1/1/2008");
	var_Chart->PutAllowInsideZoom(VARIANT_TRUE);
	var_Chart->PutAllowResizeInsideZoom(VARIANT_FALSE);
	var_Chart->PutInsideZoomOnDblClick(VARIANT_FALSE);
	var_Chart->GetDefaultInsideZoomFormat()->PutBackColorChart(255);
	EXG2ANTTLib::IInsideZoomsPtr var_InsideZooms = var_Chart->GetInsideZooms();
		var_InsideZooms->PutSplitBaseLevel(VARIANT_FALSE);
		var_InsideZooms->PutDefaultWidth(18);
		var_InsideZooms->Add("1/4/2008")->PutAllowInsideFormat(VARIANT_FALSE);
spG2antt1->EndUpdate();

The following C# sample shows how can I change the background color for a time unit, in the chart area:

axG2antt1.BeginUpdate();
EXG2ANTTLib.Chart var_Chart = axG2antt1.Chart;
	var_Chart.LevelCount = 2;
	var_Chart.FirstVisibleDate = "1/1/2008";
	var_Chart.AllowInsideZoom = true;
	var_Chart.AllowResizeInsideZoom = false;
	var_Chart.InsideZoomOnDblClick = false;
	var_Chart.DefaultInsideZoomFormat.BackColorChart = 255;
	EXG2ANTTLib.InsideZooms var_InsideZooms = var_Chart.InsideZooms;
		var_InsideZooms.SplitBaseLevel = false;
		var_InsideZooms.DefaultWidth = 18;
		var_InsideZooms.Add("1/4/2008").AllowInsideFormat = false;
axG2antt1.EndUpdate();

The following VFP sample shows how can I change the background color for a time unit, in the chart area:

with thisform.G2antt1
	.BeginUpdate
	with .Chart
		.LevelCount = 2
		.FirstVisibleDate = {^2008-1-1}
		.AllowInsideZoom = .T.
		.AllowResizeInsideZoom = .F.
		.InsideZoomOnDblClick = .F.
		.DefaultInsideZoomFormat.BackColorChart = 255
		with .InsideZooms
			.SplitBaseLevel = .F.
			.DefaultWidth = 18
			.Add({^2008-1-4}).AllowInsideFormat = .F.
		endwith
	endwith
	.EndUpdate
endwith