@Test
public void toLabel_negative() throws ParseException {

	Date start =  new SimpleDateFormat("yyyy/MM/dd z HH:mm:ss").parse("2011/05/13 EST 24:00:00");
	Date expect =  new SimpleDateFormat("yyyy/MM/dd z HH:mm:ss").parse("2011/05/11 EST 24:00:00");
	assertEquals(expect, DateUtils.addTime(start, Calendar.DAY_OF_MONTH, -2));
}