old_contents: #!/usr/bin/env python
  from django.db import models
  from django.utils.translation import ugettext_lazy as _
  
  from datetime import datetime
  
  
  
  class PublisherMnager(models.Manager):
      def all_published(self):
          return super(PublisherMnager, self).get_query_set().filter(
                  date_available__lte=datetime.now(), published=True)
  
  
  class Published(models.Model):
  
      date_available = models.DateTimeField(_(u"Date available"),
              default=datetime.now, null=True)
      published = models.BooleanField(_(u"Published"), default=False)
  
      objects = PublisherMnager()
  
      class Meta:
          abstract = True
  
      def is_published(self):
          return self.published and \
                  self.date_available.replace(tzinfo=None) <= datetime.now()
  
new_contents: #!/usr/bin/env python
  from django.db import models
  from django.utils.translation import ugettext_lazy as _
  
  from datetime import datetime
  
  
  
  class PublishedMnager(models.Manager):
      def all_published(self):
          return super(PublisherMnager, self).get_query_set().filter(
                  date_available__lte=datetime.now(), published=True)
  
  
  class Published(models.Model):
  
      date_available = models.DateTimeField(_(u"Date available"),
              default=datetime.now, null=True)
      published = models.BooleanField(_(u"Published"), default=False)
  
      objects = PublishedMnager()
  
      class Meta:
          abstract = True
  
      def is_published(self):
          return self.published and \
                  self.date_available.replace(tzinfo=None) <= datetime.now()
  
subject: Change name manager Publisher to Published