from django.db import models

class QuerySetManager(models.Manager):
    def get_query_set(self):
        return self.model.QuerySet(self.model)

# Using it in a model:

from django.db.models.query import QuerySet
import datetime

class Entry(models.Model):
   ...
   objects = QuerySetManager()
   ...
   class QuerySet(QuerySet):
        def on_date(self, date):
            next = date + datetime.timedelta(days = 1)
            return self.filter(
                posted__gt = date,
                posted__lt = next
            )

# Now you can get entries on a specific day like so:
#   Entry.objects.all().on_date(datetime.date.today())