public XMLGregorianCalendar DateToXmlGregorianCalendar(Date d) {
	GregorianCalendar gc = new GregorianCalendar();
	gc.setTime(d);
	return new XMLGregorianCalendarImpl(gc);
	}
 
	public Date xmlGregorianCalendarToDate(XMLGregorianCalendar xgc) {
	return xgc.toGregorianCalendar().getTime();
	}

The above code can be used to call the Gregorian Calender Converter which should be placed in the .util package.

document.setExpirationDate(XMLGregorianConverter.DateToXmlGregorianCalendar(new Date(1, 0, 0)));

Once the Converter is called this code can be used to set the actual time; it is worth noting that the base date is Jan, 1 1899. It may take some trial and error to get the dates correct.