Bug 118644 Hint for Date Time Parameters
The hint you give for date time parameters (Please enter date ... pattern: MM/DD/YYYY ....) is only true if the date is unformatted. If you apply a format, you must enter it according to it. So it's quite confusing!
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
private void popupFormatBuilder( boolean refresh )
	{
		String type = getSelectedDataType( );
		int style;
		if ( DesignChoiceConstants.PARAM_TYPE_BOOLEAN.equals( type ) )
		{
			return;
		}
		if ( DesignChoiceConstants.PARAM_TYPE_STRING.equals( type ) )
		{
			style = FormatBuilder.STRING;
		}
		else if ( DesignChoiceConstants.PARAM_TYPE_DATETIME.equals( type ) )
		{
			style = FormatBuilder.DATETIME;
		}
		else
		{
			style = FormatBuilder.NUMBER;
		}
		FormatBuilder formatBuilder = new FormatBuilder( style );
		formatBuilder.setInputFormat( formatCategroy, formatPattern );
		formatBuilder.setPreviewText( defaultValue );
		if ( formatBuilder.open( ) == OK )
		{
			formatCategroy = getCategroy( (String) formatBuilder.getResult( ) );
			formatPattern = getPattern( (String) formatBuilder.getResult( ) );
			updateFormatField( );
			if ( refresh )
			{