Very strange behavior with to_date and format 'yddd' after 31/12/2009

Question

Hi, I have the following PL/SQL code which retrieve a date from a production batch code as fallow:
DECLARE
dtmDateFabric DATE;
BEGIN
-- on teste si l'on peut reconstituer la date fabric à partir du code lot
dtmDateFabric := TO_DATE ('9348', 'yddd');
DBMS_OUTPUT.put_line ('dtmdatefabric ' || dtmDateFabric);
END;
batch code is constitued like this: YDDD year of production and day number in year.
This code was perfectly working before 2010 and it used to return December 14, 2009.
And now the same code returns December 14, 2019.
And I can't use 'rddd' as format.
Any idea to resolve this issue ?
Thank's for help.
Olivier

Answer 1

It's not strange at all, we are in 2010 now, so if don't specify the decade, century and millennium it takes the current: 2 (millennium) 0(century) 1(decade) and your year becomes 2019...
You have to add a byte to your year format to specify the decade:
SQL> DECLARE
  2  dtmDateFabric DATE;
  3  BEGIN
  4  -- on teste si l'on peut reconstituer la date fabric à partir du code lot
  5  dtmDateFabric := TO_DATE ('09348', 'yyddd');
  6  DBMS_OUTPUT.put_line ('dtmdatefabric ' || dtmDateFabric);
  7  END;
  8  /
dtmdatefabric 14-12-2009 00:00:00
Procedura PL/SQL completata correttamente.And you'll be ok untill 2099...
Max
[My Italian Oracle blog|http://oracleitalia.wordpress.com/2010/01/07/creare-documenti-office-da-plsql/]
Edited by: Massimo Ruocchio on Jan 8, 2010 4:40 PM
Added explaination