Python-сообщество

 date = models.DateTimeField(blank=True, auto_now_add=True)

 <QuerySet [{'some': 123, 'date': datetime.datetime(2018, 5, 29, 1, 21, 35, 861400, tzinfo=<UTC>)

 def myconverter(o):
    if isinstance(o, datetime.datetime):
        return o.__str__()
obj_all = Some.objects.values()[0:3]
json.dumps(obj_all, default=myconverter)

 # TIME_ZONE = 'UTC'
TIME_ZONE = 'Europe/Moscow'
USE_I18N = True
USE_L10N = True
USE_TZ = True
DATETIME_FORMAT = "U"
DATETIME_INPUT_FORMATS = ("%s",)

 class UCDateTimeField(DateTimeField):
    def pre_save(self, model_instance, add):
        if self.auto_now or (self.auto_now_add and add):
            value = datetime.datetime.now()
            setattr(model_instance, self.attname, value)
            return value
        else:
            value = getattr(model_instance, self.attname)
            if not isinstance(value, datetime):
                # assume that the value is a timestamp if it is not a datetime
                value = datetime.fromtimestamp(int(value))
                # an exception might be better than an assumption
                setattr(model_instance, self.attname, value)
            return super(UCDateTimeField, self).pre_save(model_instance, add)

 date = UCDateTimeField(blank=True, auto_now_add=True)