Bug 202121 setDateFormat does not working
If you want to set date format of the table column style you have to use setDateTimeFormatCategory and setDateTimeFormat instead of setDateFormatCategory and setDateFormat. If you will try to use setDateFormatCategory in the first case in xml-source you will see that your style contains dateFormat property. This property is not working at all, in the second case in xml-source you will see that your style contains dateTimeFormat property. I think it will be better if the result of setDateTimeFormatCategory and setDateFormatCategory will be the same.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/parser/EngineIRVisitor.java
/**
	 * the non-inheritable report style
	 */
	StyleDeclaration inheritableReportStyle;
	/**
	 * Used to fix half-baked handle, such as:
	 *   fix the new added empty cell created in format irregular table or grid.
	 *   fix default master page.
	 */
	long newCellId = -1;
	
	/**
	 * used to remember the nesting count of the extended items. and change the
	 * data item's needRefreshMapping while it is in a extended item.
	 */
	int extendedItemNestingCount = 0;
	
	/**
	 * constructor
	 * 
	 * @param handle
	 *            the entry point to the DE report design IR
	 * 
	 */
	public EngineIRVisitor( ReportDesignHandle handle )
	{
		super( );
		this.handle = handle;
	}
	/**