valid_nth_kday_p 2831 ext/date/date_core.c if (!valid_nth_kday_p(y, m, n, k, sg, valid_nth_kday_p 3591 ext/date/date_core.c if (!valid_nth_kday_p(y, m, n, k, sg, valid_nth_kday_p 7594 ext/date/date_core.c if (!valid_nth_kday_p(y, m, n, k, sg,