Bug 182284 Error message props up after previewing a report with a group on date type column
Use the attached rptdesign file preview Expected Result: Data is grouped without error message. Actual result: error message props up.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/group/GroupCalculatorFactory.java
{
			return null;
		}
		try
		{
			switch ( interval )
			{
				case IGroupDefinition.YEAR_INTERVAL :
					return new YearGroupCalculator( intervalStart,
							intervalRange );
				case IGroupDefinition.MONTH_INTERVAL :
					return new MonthGroupCalculator( intervalStart,
							intervalRange );
				case IGroupDefinition.QUARTER_INTERVAL :
					return new QuarterGroupCalculator( intervalStart,
							intervalRange );
				case IGroupDefinition.WEEK_INTERVAL :
					return new WeekGroupCalculator( intervalStart,
							intervalRange );
				case IGroupDefinition.DAY_INTERVAL :
					return new DayGroupCalculator( intervalStart, intervalRange );
				case IGroupDefinition.HOUR_INTERVAL :
					return new HourGroupCalculator( intervalStart,
							intervalRange );
				case IGroupDefinition.MINUTE_INTERVAL :
					return new MinuteGroupCalculator( intervalStart,
							intervalRange );
				case IGroupDefinition.SECOND_INTERVAL :
					return new SecondGroupCalculator( intervalStart,
							intervalRange );