[Koha-zebra] order by date of publication ?

[Henri-Damien LAURENT]

Hi,
I think I have a problem of sorting with zebra.
Indeed,
here is a list which comes from ccfls
I asked for walt whitman and walt as author, and asked for order by
date-of-Publication newest to oldest.
1997 comes First
then 1999 then 1997 again, and 1994

here comes the list
 
To the soul : Thomas Hampson sings the poetry of Walt Whitman / by
Hampson, Thomas.

- 1997 - EMI Classics, ; New York : - 1 compact disc (74:49 min)

Copies available at: Meadville Public Library (1),
CDCD B Hampson
    Walt Whitman : selected poems, 1855-1892 : a new edition / by
Whitman, Walt,

- 1999 - St. Martin's Press, ; New York : - xxviii, 530 p. : ; 25 cm.

Copies available at: Meadville Public Library (1),
NF811.3 Whitman
    Walt Whitman / by Whitman, Walt,

- 1997 - Sterling Pub., ; New York : - 48 p. : : Includes index. ; 26 cm.

Copies available at: Meadville Public Library (1),
JNFJUV 811 Whitman
    Walt Whitman / by Whitman, Walt,

- 1997 - Sterling Pub., ; New York : - 48 p. : : Includes index. ; 26 cm.

Copies available at: Meadville Public Library (1),
YANFYA 811.3 Whitman
    Walt Whitman / by Loewen, Nancy,

- 1994 - Creative Editions, ; Mankato, Minn. : - 45, [1] p. : ; 29 cm.

Copies available at: Meadville Public Library (1),
NF811 Loewen



I took ccfls to show that it was not a frenchy problem, but a global one.

On a french catalogue equiped with rel_30, with date of publication
Newest to oldest, we have :
2006, 2004,2003,1999,1857 !!, 1985, 1980, 1980
and date of publication is indexed as !:y

Titre

Paul de Tarse en Méditerranée
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/detail.pl?biblionumber=53331>
, recherches autour de la navigation dans l'Antiquité | Ac 27-28, 16

Chantal Reynier
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/search.pl?q=au:Chantal%20Reynier>
- 2006 - les Éd. du Cerf Description : - 288 p. ; 22 cm

Histoire de Paul de Tarse
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/detail.pl?biblionumber=54103>
, le voyageur du Christ

Jerôme Murphy-O'Connor
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/search.pl?q=au:Jer%C3%B4me%20Murphy-O%27Connor>
- 2004 - Ed. du Cerf Description : - 315 p. ; 22 cm

Tarse et Jerusalem
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/detail.pl?biblionumber=54360>
, la double culture de l'apôtre Paul en Galates 3,6-4,7

Marc Rastoin,...
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/search.pl?q=au:Marc%20Rastoin%2C...>
- 2003 - Ed. Pontificio Istituto Biblico Description : - 1 vol. (376 p.)
; 24 cm

Jacob Taubes et Paul de Tarse
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/detail.pl?biblionumber=54033>
, Notes de lecture

Simon C. Mimouni
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/search.pl?q=au:Simon%20C.%20Mimouni>
- 1999 - Peeters Description : - [10] p. ; 25 cm

Opera
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/detail.pl?biblionumber=3230>


Diodore de Tarse
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/search.pl?q=au:Diodore%20de%20%3Cspan%20class%3Dterm%3ETarse%3C%2Fspan%3E>
- 1857 Description :

Jésus de Nazareth et Paul de Tarse
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/detail.pl?biblionumber=6359>


Christophe Senft
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/search.pl?q=au:Christophe%20Senft>
- 1985 - Labor et Fides Description :

Paul de Tarse
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/detail.pl?biblionumber=11540>
, Apôtre du notre temps

contributions de G. Benelli ... [et al.]
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/search.pl?q=au:contributions%20de%20G.%20Benelli%20...%20%5Bet%20al.%5D>
- 1979 - Abbaye de S. Paul h.l.m Description : - 806 p. ; 24 cm

Commentarii in Psalmos I-L [1-50]
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/detail.pl?biblionumber=11890>


Diodore de Tarse
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/search.pl?q=au:Diodore%20de%20%3Cspan%20class%3Dterm%3ETarse%3C%2Fspan%3E>
- 1980 - Brepols Description : - CXX-328p. ; 25cm

Paul de Tarse
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/detail.pl?biblionumber=13309>
, congrès

[organisé par ] l' ACFEB, Strasbourg, 1995
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/search.pl?q=au:%5Borganis%C3%A9%20par%20%5D%20l%27%20ACFEB%2C%20Strasbourg%2C%201995>
- 1996 - Ed. du Cerf Description : - 373p. ; 22cm

Les Fragments de Tarse au Louvre
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/detail.pl?biblionumber=22023>


Léon Alexandre Heuzey
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/search.pl?q=au:L%C3%A9on%20Alexandre%20%20Heuzey>
- 1876 Description :

Paul de Tarse
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/detail.pl?biblionumber=22920>


Joseph Holzner
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/search.pl?q=au:Joseph%20%20Holzner>
- 1950 - Alsatia Description : - 577p. ; 24cm

Saul de Tarse
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/detail.pl?biblionumber=27766>
, Lettres à une jeune église

Jean Paul Benoit
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/search.pl?q=au:Jean%20Paul%20%20Benoit>
Description : - 214p.

Paul de Tarse
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/detail.pl?biblionumber=42201>


Michel A. Hubaut
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/search.pl?q=au:Michel%20A.%20Hubaut>
- 1989 - Desclée Description : - 143 p. ; 22 cm

Le Psautier chez les Pères
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/detail.pl?biblionumber=48415>


  - 1994 - Centre d'analyse et de documentation patristiques Description
: - 310p. ; 21cm

Le Psautier chez les Pères
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/detail.pl?biblionumber=48417>


  - 1994 - Centre d'analyse et de documentation patristiques Description
: - 310p. ; 21cm

Paul de Tarse
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/detail.pl?biblionumber=48697>
, un homme aux prises avec Dieu

Daniel Marguerat
<https://admin-catalogue.iptheologie.fr/cgi-bin/koha/catalogue/search.pl?q=au:Daniel%20%20Marguerat>
- 1999 - Ed. du Moulin Description : - 109p. ; 18cm



Moreover, I have to state that :
in France, 210$d is supposed to have publication date but also sometimes
some information such as c for copyright, and other terms...
Maybe it could be overcome by using null words for sorting dates (I hope
so). Is this true ?
Hoping to have an answer soon.
-- 
Henri-Damien LAURENT