Bug 179898 Date/Time type X-Axis labels are not correct when set grouping [0001]
Description: Date/Time type X-Axis labels are not correct when set grouping. Build number: 2.2.0.v20070328-0630 Steps to reproduce: 1. New a Bar Chart with Date/Time type X-Axis with values as 4/1/2005 10:12 AM 4/1/2005 11:15 AM 4/1/2005 7:15 AM 2. Enable X Series Grouping, set Type as "DateTime", Unit as "Day", Interval as 1, and Aggregate Expression as "Sum". 3. Preview. Expected result: X-Axis label should be "4/1/2005" Actual result: X-Axis label is "2005" Error log: N/A
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/util/CDateTime.java
cPrev = (Calendar) dsi.last( );
			dsi.reset( );
			while ( dsi.hasNext( ) )
			{
				cCurr = (Calendar) dsi.next( );
				if ( cCurr != null
						&& cPrev != null
						&& cCurr.get( iaUnitTypes[k] ) != cPrev.get( iaUnitTypes[k] ) )
				{
					return iaUnitTypes[k]; 
					
				}
				if ( cCurr != null )
				{
					cPrev = cCurr;
				}
			}
		}
		
		return Calendar.YEAR;
	}
	/**
	 * Walks through all values in a datetime array and computes the least
	 * significant unit for which a difference was noted.
	 * 
	 * @param cdta
	 *            A datetime array for which the least significant unit
	 *            difference is to be computed
	 * 
	 * @return The least significant unit for which a difference in datetime