public void testSubtractDays() {
        // This is a test for a bug in version 1.0. The dayOfMonth range
        // duration field did not match the monthOfYear duration field. This
        // caused an exception to be thrown when subtracting days.
        DateTime dt = new DateTime
            (1112306400000L, GJChronology.getInstance(DateTimeZone.forID("Europe/Berlin")));
        YearMonthDay ymd = dt.toYearMonthDay();
        while (ymd.toDateTimeAtMidnight().getDayOfWeek() != DateTimeConstants.MONDAY) { 
            ymd = ymd.minus(Period.days(1));
        }
    }