@Test
public void testYesterdayZero() {

	Calendar cal = Calendar.getInstance();
	cal.set(Calendar.DAY_OF_YEAR, 1);
	cal.set(Calendar.HOUR_OF_DAY, 0);
	cal.set(Calendar.MINUTE, 0);
	cal.set(Calendar.SECOND, 0);
	cal.set(Calendar.MILLISECOND, 0);
	Date yesterdayZero = TaskHelper.yesterdayZero(cal.getTime());
	Assert.assertEquals(cal.getTimeInMillis(), yesterdayZero.getTime() + 3600L * 1000 * 24);
}