models.py

class Article(models.Model):
	@models.permalink
	def get_absolute_url(self):
		return reverse('article_permalink', kwargs={
			'year': self.published_at.year,
			'month': self.published_at.month,
			'day': self.published_at.day,
			'slug': self.slug,
		})

urls.py

urlpatterns = patterns('django.views.generic.date_based',
	url(r'^(?P<year>\d{4})/(?P<month>[a-z]{3})/(?P<day>[0-9]{2})/(?P<slug>[a-zA-Z0-9_\-]+)/$', 'object_detail', {
		'queryset': Article.published_objects.all(),
		'date_field': 'published_at',
		'template_object_name': 'article',
	}, name='article_permalink'),
)