public Calendar ceil(long t) {
        Calendar cal = new GregorianCalendar(Locale.US);
        cal.setTimeInMillis(t);
        return ceil(cal);
    }
@Test(timeout = 1000)
    @Issue("JENKINS-12357")
    public void testCeil3_DoW7() throws Exception {
        // similar to testCeil3, but DoW=7 may stuck in an infinite loop
        CronTab x = new CronTab("0 0 1 * 7");
        Calendar c = new GregorianCalendar(2010, Calendar.JANUARY, 1, 15, 55);
        // the first such day in 2010 is Aug 1st
        compare(new GregorianCalendar(2010, Calendar.AUGUST, 1, 0, 0), x.ceil(c));
    }