Thread

1. CC Date format code defaults to current centry

   Joe Brown <joebrown@rclooke.com> — 2005-03-08T17:40:02Z

   joe=> select to_date('19450323','CCYYMMDD');
     to_date  
   ------------
    2045-03-23
   (1 row)
   
   joe=> select to_date('19450323','YYYYMMDD');
     to_date  
   ------------
    1945-03-23
   (1 row)
   
   I thought the former would be "more" correct.  But it seems I am mistaken.
   
   

2. Re: CC Date format code defaults to current centry

   Bruce Momjian <pgman@candle.pha.pa.us> — 2005-03-14T02:24:33Z

   Joe Brown wrote:
   > joe=> select to_date('19450323','CCYYMMDD');
   >   to_date  
   > ------------
   >  2045-03-23
   > (1 row)
   > 
   > joe=> select to_date('19450323','YYYYMMDD');
   >   to_date  
   > ------------
   >  1945-03-23
   > (1 row)
   > 
   > I thought the former would be "more" correct.  But it seems I am mistaken.
   
   Uh, 1945 _is_ in the 20th century, but I can see how it is confusing.
   
   -- 
     Bruce Momjian                        |  http://candle.pha.pa.us
     pgman@candle.pha.pa.us               |  (610) 359-1001
     +  If your life is a hard drive,     |  13 Roberts Road
     +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073
   
   

3. Re: CC Date format code defaults to current centry

   Andre Maasikas <andre@abs.ee> — 2005-03-14T11:11:58Z

   Bruce Momjian wrote:
   > Joe Brown wrote:
   > 
   >>joe=> select to_date('19450323','CCYYMMDD');
   >>  to_date  
   >>------------
   >> 2045-03-23
   >>(1 row)
   >>
   >>joe=> select to_date('19450323','YYYYMMDD');
   >>  to_date  
   >>------------
   >> 1945-03-23
   >>(1 row)
   >>
   >>I thought the former would be "more" correct.  But it seems I am mistaken.
   > 
   > 
   > Uh, 1945 _is_ in the 20th century, but I can see how it is confusing.
   > 
   Yes, but the other way around: to_date('19450323','CCYYMMDD')
   shoold be a year in the 19th century?
   
   ps another db seems to disallow CC on input - maybe because one can
   get into weird situations like to_date('2005 18','YYYY CC') or something 
   similar.
   
   Andre
   
   
   

4. Re: [BUGS] CC Date format code defaults to current centry

   Karel Zak <zakkr@zf.jcu.cz> — 2005-03-17T09:50:51Z

   On Sun, 2005-03-13 at 21:24 -0500, Bruce Momjian wrote:
   > Joe Brown wrote:
   > > joe=> select to_date('19450323','CCYYMMDD');
   > >   to_date  
   > > ------------
   > >  2045-03-23
   > > (1 row)
   > > 
   > > joe=> select to_date('19450323','YYYYMMDD');
   > >   to_date  
   > > ------------
   > >  1945-03-23
   > > (1 row)
   > > 
   > > I thought the former would be "more" correct.  But it seems I am mistaken.
   > 
   > Uh, 1945 _is_ in the 20th century, but I can see how it is confusing.
   
   It ignored CC value if there was YY (YYYY, ..). And YY=45 is 2045:
   
    /*
     * 2-digit year
     */
    if (tmfc->year < 70)
      tmfc->year += 2000;
    else
      tmfc->year += 1900;
   
   
    I think it's very special case when you define YY and CC and code
   should detects it and counts year as (CC-1)*100+YY. The right answers:
   
   CC+YY
   
   test=# select to_date('20450112', 'CCYYDDMM');
     to_date
   ------------
    1945-12-01
   
   CC+Y
   
   test=# select to_date('2090112', 'CCYDDMM');
     to_date
   ------------
    1909-12-01
   
   
   For YYY/YYYY it ignore CC option.
   
   The patch (with docs changes) is in the attachment.
   
   	Karel
   
   
   -- 
   Karel Zak <zakkr@zf.jcu.cz>
   

5. Re: [BUGS] CC Date format code defaults to current centry

   Tom Lane <tgl@sss.pgh.pa.us> — 2005-03-25T16:09:30Z

   Karel Zak <zakkr@zf.jcu.cz> writes:
   >  I think it's very special case when you define YY and CC and code
   > should detects it and counts year as (CC-1)*100+YY. The right answers:
   > ...
   > The patch (with docs changes) is in the attachment.
   
   Applied to HEAD and 8.0.
   
   			regards, tom lane