public Calendar ceil(long t) {
        Calendar cal = new GregorianCalendar(Locale.US);
        cal.setTimeInMillis(t);
        return ceil(cal);
    }
@Test
    public void testCeil2() throws Exception {
        // make sure that lower fields are really reset correctly
        CronTab x = new CronTab("15,45 3 * * *");
        Calendar c = new GregorianCalendar(2000, Calendar.MARCH, 1, 2, 30);
        compare(new GregorianCalendar(2000, Calendar.MARCH, 1, 3, 15), x.ceil(c));
    }