public Calendar ceil(long t) {
        Calendar cal = new GregorianCalendar(Locale.US);
        cal.setTimeInMillis(t);
        return ceil(cal);
    }
@Test public void hashedMinute() throws Exception {
        long t = new GregorianCalendar(2013, Calendar.MARCH, 21, 16, 21).getTimeInMillis();
        compare(new GregorianCalendar(2013, Calendar.MARCH, 21, 17, 56), new CronTab("H 17 * * *", Hash.from("stuff")).ceil(t));
        compare(new GregorianCalendar(2013, Calendar.MARCH, 21, 16, 56), new CronTab("H * * * *", Hash.from("stuff")).ceil(t));
        compare(new GregorianCalendar(2013, Calendar.MARCH, 21, 16, 56), new CronTab("@hourly", Hash.from("stuff")).ceil(t));
        compare(new GregorianCalendar(2013, Calendar.MARCH, 21, 17, 20), new CronTab("@hourly", Hash.from("junk")).ceil(t));
        compare(new GregorianCalendar(2013, Calendar.MARCH, 22, 13, 56), new CronTab("H H(12-13) * * *", Hash.from("stuff")).ceil(t));
    }