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
static final double DEFAULT_MASTERPAGE_TOP_MARGIN = 1; 
	static final double DEFAULT_MASTERPAGE_LEFT_MARGIN = 1.25; 
	static final double DEFAULT_MASTERPAGE_BOTTOM_MARGIN = 1; 
	static final double DEFAULT_MASTERPAGE_RIGHT_MARGIN = 1.25; 
	
	/**
	 * logger used to log the error.
	 */
	protected static Logger logger = Logger.getLogger( EngineIRVisitor.class
			.getName( ) );
	/**
	 * current report element created by visitor
	 */
	protected Object currentElement;
	/**
	 * Factory IR created by this visitor
	 */
	protected Report report;
	/**
	 * report design handle
	 */
	protected ReportDesignHandle handle;
	/**
	 * the CSSEngine
	 */
	protected CSSEngine cssEngine;
	/**
	 * the inheritable report style
	 */
	StyleDeclaration nonInheritableReportStyle;