The HijrahDate class incorrectly calculates the aligned-day-of-week field. It based the calculation on the day-of-week, when it should be based on the day-of-month.

HijrahDate line 372:
 case ALIGNED_DAY_OF_WEEK_IN_MONTH: return ((getDayOfWeek() - 1) % 7) + 1;
should be:
 case ALIGNED_DAY_OF_WEEK_IN_MONTH: return ((dayOfMonth - 1) % 7) + 1;

Proposed test case:

    public void test_alignedDayOfWeekInMonth() {
        for (int dom = 1; dom <= 29; dom++) {
            HijrahDate date = HijrahChronology.INSTANCE.date(1437, 10, dom);
            assertEquals(date.getLong(ALIGNED_WEEK_OF_MONTH), ((dom - 1) / 7) + 1);
            assertEquals(date.getLong(ALIGNED_DAY_OF_WEEK_IN_MONTH), ((dom - 1) % 7) + 1);
            date = date.plus(1, ChronoUnit.DAYS);
        }
    }

Spotted by Martin Baker:
https://github.com/ThreeTen/threetenbp/pull/47
https://github.com/kemokid