def get_date_field(self):
        if self.date_field is None:
            raise ImproperlyConfigured("%s.date_field is required." % self.__class__.__name__)
        return self.date_field
Get the name of the date field to be used to filter by.
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/django/views/generic/dates.py/DateMixin.get_date_field