Version : Oracle 8
OS : Solaris

I have a table containing a date column. On one of the records I have the following problems :

SQL> alter session set nls_date_format = 'dd/mm/yyyy';

Session altered.

SQL> select date_ouverture from contrat59.t_pc_element_service_commande where id_element_service_commande= 11983;

DATE_OUVER
----------
27/01/5555

SQL> select to_char(date_ouverture,'YYYYMMDD') from contrat59.t_pc_element_service_commande where id_element_service_commande= 11983;

TO_CHAR(
--------
00000000

SQL> select date_ouverture+1 from contrat59.t_pc_element_service_commande where id_element_service_commande= 11983;

ERROR at line 1:
ORA-01841: (full) year must be between -4713 and +9999, and not be 0


Can somebody explain what's going on ?