There is a way to get some "inconsistent" data (date with year 0) in the database with plain SQL. 

Example:

SQL> ALTER session SET nls_date_format='DD/MM/YYYY';
 
Session altered.
 
SQL> DESC td;
 Name                                      NULL?    Type
 ----------------------------------------- -------- ----------------------------
 
 C                                                  DATE
 
SQL> INSERT INTO td VALUES(to_date('00/00/0000'));
INSERT INTO td VALUES(to_date('00/00/0000'))
                              *
ERROR at line 1:
ORA-01847: day of month must be BETWEEN 1 AND last day of month
 
SQL> INSERT INTO td VALUES('01/00/0000');
INSERT INTO td VALUES('01/00/0000')
                      *
ERROR at line 1:
ORA-01843: NOT a valid month
 
 
SQL> INSERT INTO td VALUES('01/01/0000');
INSERT INTO td VALUES('01/01/0000')
                      *
ERROR at line 1:
ORA-01841: (full) year must be BETWEEN -4713 AND +9999, AND NOT be 0
 
SQL> INSERT INTO td VALUES(TO_DATE('01/01/0001','DD/MM/YYYY')-1)
  2  ;
 
1 row created.
 
SQL> SELECT * FROM td;
 
C
----------
31/12/0000
 
SQL> SELECT * FROM v$version;
 
BANNER
----------------------------------------------------------------
Oracle DATABASE 10g Enterprise Edition Release 10.1.0.2.0 - Prod
PL/SQL Release 10.1.0.2.0 - Production
CORE    10.1.0.2.0      Production
TNS FOR 32-bit Windows: Version 10.1.0.2.0 - Production
NLSRTL Version 10.1.0.2.0 - Production
 
SQL> SELECT to_char(c,'DD/MM/YYYY') FROM td;
 
TO_CHAR(C,
----------
00/00/0000
 
SQL> SELECT * FROM nls_session_parameters;
 
PARAMETER                      VALUE
------------------------------ ----------------------------------------
NLS_LANGUAGE                   FRENCH
NLS_TERRITORY                  FRANCE
NLS_CURRENCY                   Ç
NLS_ISO_CURRENCY               FRANCE
NLS_NUMERIC_CHARACTERS         ,
NLS_CALENDAR                   GREGORIAN
NLS_DATE_FORMAT                DD/MM/YYYY
NLS_DATE_LANGUAGE              FRENCH
NLS_SORT                       FRENCH
NLS_TIME_FORMAT                HH24:MI:SSXFF
NLS_TIMESTAMP_FORMAT           DD/MM/RR HH24:MI:SSXFF
 
PARAMETER                      VALUE
------------------------------ ----------------------------------------
NLS_TIME_TZ_FORMAT             HH24:MI:SSXFF TZR
NLS_TIMESTAMP_TZ_FORMAT        DD/MM/RR HH24:MI:SSXFF TZR
NLS_DUAL_CURRENCY              Ç
NLS_COMP                       BINARY
NLS_LENGTH_SEMANTICS           BYTE
NLS_NCHAR_CONV_EXCP            FALSE
 
17 rows selected.