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
allowBlank.setEnabled( true );
				allowNull.setEnabled( true );
				doNotEcho.setEnabled( true );
				if ( dirtyProperties.containsKey( CHECKBOX_ALLOW_BLANK ) )
				{
					allowBlank.setSelection( getProperty( CHECKBOX_ALLOW_BLANK ) );
				}
				else
				{
					allowBlank.setSelection( inputParameter.allowBlank( ) );
				}
				if ( dirtyProperties.containsKey( CHECKBOX_ALLOW_NULL ) )
				{
					allowNull.setSelection( getProperty( CHECKBOX_ALLOW_NULL ) );
				}
				else
				{
					allowNull.setSelection( inputParameter.allowNull( ) );
				}
			}
			else
			{
				allowBlank.setEnabled( false );
				allowNull.setEnabled( false );
			}
			if ( DesignChoiceConstants.PARAM_CONTROL_TEXT_BOX.equals( getSelectedControlType( ) ) )
			{
				doNotEcho.setEnabled( true );
				if ( dirtyProperties.containsKey( CHECKBOX_DO_NOT_ECHO ) )
				{