@Test
public void testIsPublicHoliday() throws Exception {

    final Calendar calendar = GregorianCalendar.getInstance();
    calendar.set(2015, 0, 1);
    assertTrue(DateUtil.isPublicHoliday(calendar.getTime()));
    calendar.set(2016, 2, 28); //28 March is "Ostermontag"
    assertTrue(DateUtil.isPublicHoliday(calendar.getTime()));
    calendar.set(2015, 5, 5); // 5 June
    assertFalse(DateUtil.isPublicHoliday(calendar.getTime()));
}