[ZWeb] Problem using the search engine on zope.org

[Paolo Dina]

Hi, just this morning i experienced a problem using the search engine 
of Zope web site.

How to reproduce:
- Click on Search link at the top of the page
- containing the text: xml
- with the type of: Software Product
- modified since: ever
- Click on search

well.. Found 41 items matching "xml"
... blabla ...
... blabla ...
... blabla ...

Now, click on Last Modified to order results by date and you will get 
the error.
The same error happens when you click on Author or Title link.

P.S.: the problem doesn't occour if the search is accomplished using 
the Search/Go form at the top of the page.

A quick link to the error is:
http://www.zope.org/SiteIndex/search?text_content=xml&meta_type%3Alist=Software%2bProduct&date_usage=range%3Amin&date%3Adate=1969%2F12%2F31%2b19%3A00%3A00%2bUS%2FEastern&sort_on=date

The error instead is:

System Unavailable
This site is currently experiencing technical difficulties. Please 
contact the site

administrator for more information. For additional technical 
information, please refer to

the HTML source for this page. Thank you for your patience.

  Error type:  Invalid Date-Time String
  Error value: 1969/12/31+19:00:00+US/Eastern

Traceback (obtained from More Information.. button) is:

<!--
Traceback (innermost last):
   File /usr/local/base/org/Products/Hotfix_2002-04-15/__init__.py, 
line 51, in publish_module
   File 
/usr/local/base/Zope-2.3.2-modified/lib/python/ZPublisher/Publish.py, 
line 187, in publish
   File 
usr/local/base/Zope-2.3.2-modified/lib/python/Zope/__init__.py, line 
221, in zpublisher_exception_hook(Object: ApplicationDefaultPermissions)
   File 
/usr/local/base/Zope-2.3.2-modified/lib/python/ZPublisher/Publish.py, 
line 136, in publish
   File 
/usr/local/base/Zope-2.3.2-modified/lib/python/ZPublisher/HTTPRequest.py, 
line 507, in processInputs
   File 
/usr/local/base/Zope-2.3.2-modified/lib/python/ZPublisher/Converters.py, 
line 178, in field2date
   File 
/usr/local/base/Zope-2.3.2-modified/lib/python/DateTime/DateTime.py, 
line 708, in __init__
   File 
/usr/local/base/Zope-2.3.2-modified/lib/python/DateTime/DateTime.py, 
line 985, in _parse
Invalid Date-Time String: (see above)

-->

Paolo Dina