date_s_valid_civil_p 9216 ext/date/date_core.c     rb_define_singleton_method(cDate, "valid_civil?", date_s_valid_civil_p, -1);
date_s_valid_civil_p 9217 ext/date/date_core.c     rb_define_singleton_method(cDate, "valid_date?", date_s_valid_civil_p, -1);