How to make Django's "DATETIME_FORMAT" active?

Question

Where should DATETIME_FORMAT be placed for it to have effect on the display of date-time in the Django admin site (Django’s automatic admin interface)?

Documentation for DATETIME_FORMAT, on page http://docs.djangoproject.com/en/1.0/ref/settings/, says:

"The default formatting to use for datetime fields on
Django admin change-list pages -- and, possibly, by
other parts of the system."

Update 1: DATETIME_FORMAT is broken (the value of it is ignored), despite the documentation. Many years ago it worked, but since then the Django implementations have been broken wrt. this feature. It seems the Django community can't decide how to fix it (but in the meantime I think they should remove DATETIME_FORMAT from the documentation or add a note about this problem to it).

I have put these lines into file "settings.py" of the website/project (not the app), but it does not seem to have any effect (after restarting the development server):

DATETIME_FORMAT = 'Y-m-d H:i:sO'

DATE_FORMAT = 'Y-m-d'

As an example "June 29, 2009, 7:30 p.m." is displayed when using Django admin site.

Django version is 1.0.2 final and Python version is 2.6.2 (64 bit). Platform: Windows XP 64 bit.

Stack Overflow question European date input in Django Admin seems to be about the exact opposite problem (and thus an apparent contradiction).

The full path to file "settings.py" is "D:\dproj\MSQall\website\GoogleCodeHost\settings.py". I now start the development server this way (in a Windows command line window):

cd D:\dproj\MSQall\website\GoogleCodeHost

set DJANGO_SETTINGS_MODULE=GoogleCodeHost.settings

python manage.py runserver 6800

There is no difference. Besides these are positively read from file "settings.py":

DATABASE_NAME

INSTALLED_APPS

TEMPLATE_DIRS

MIDDLEWARE_CLASSES

"django-admin.py startproject XYZ" does not create file "settings.py" containing DATETIME_FORMAT or DATE_FORMAT. Perhaps there is a reason for that?

The sequence "d:", "cd D:\dproj\MSQall\website\GoogleCodeHost", "python manage.py shell", "from django.conf import settings", "settings.DATE_FORMAT", "settings.DATETIME_FORMAT" outputs (as expected):

'Y-m-d H:i:sO'
'Y-m-d'

So the content of file "settings.py" is being read, but does not take effect in the Django Admin interface.

Answer 1

This will solve the particular problem that is not possible with DATETIME_FORMAT (as it is ignored in the current Django implementations despite the documentation), is dirty too and is similar to ayaz's answer (less global - will only affect the admin site list view):

Right after the line

(date_format, datetime_format,time_format) = get_date_formats()

in file (Django is usually in folder Lib/site-packages in the Python installation)

django/contrib/admin/templatetags/admin_list.py

overwrite the value of datetime_format (for a models.DateTimeField in the model):

datetime_format = 'Y-m-d H:i:sO'

And for date-only fields:

date_format = 'Y-m-d'

Restart of the web-server (e.g. development server) or logging out of the admin interface is NOT necessary for this change to take effect. A simple refresh in the web-browser is all what is required.