Bug 214197 [Regression] Auto scale does not work correctly [13]
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/computation/withaxes/AutoScale.java
else if ( ( iType & DATE_TIME ) == DATE_TIME )
		{
			final CDateTime cdt1 = (CDateTime) oMinimum;
			final CDateTime cdt2 = (CDateTime) oMaximum;
			nTicks = (int) ( Math.ceil( CDateTime.computeDifference( cdt2,
					cdt1,
					asInteger( oUnit ) ) ) / asInteger( oStep ) ) + 1;
		}
		else
		{
			throw new ChartException( ChartEnginePlugin.ID,
					ChartException.GENERATION,
					"exception.unknown.axis.type.tick.computations", 
					Messages.getResourceBundle( rtc.getULocale( ) ) );
		}
		
		
		if ( nTicks > 10000 )
		{
			nTicks = 10000;
		}
		
		if ( nTicks < 2 )
		{
			nTicks = 2;
		}
		return nTicks;
	}
	/**
	 * Returns the absolute value of the scale unit.