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Under utils/common.py, 

TIMESTAMP_FORMAT_MILLIS = '%Y-%m-%dT%H:%M:%S.%fZ'

The %f produces time with microseconds, for example: 2020-03-18T19:43:18.115783Z.


However, when interacting the AWS s3 and sns apis, I receive DateTimes like this:

2020-03-02T22:32:13.240Z
i.e. milliseconds. 

This seems like a simple change to the utils. TIMESTAMP_FORMAT_MILLIS is named as if it should be millis as well. This is seems like a simple change. Is there a reason it should be microseconds?
'MessageAttributes.entry.2.Value.BinaryValue': ['value2'],
        }
        result_str = sns_listener.create_sns_message_body(self.subscriber, action)
        result = json.loads(result_str)
        del result['MessageId']
        del result['Timestamp']
        msg = {
            'Message': 'msg',
            'Subject': 'subject',
            'Signature': 'EXAMPLEpH+..',
            'SignatureVersion': '1',
            'SigningCertURL':
                'https://sns.us-east-1.amazonaws.com/SimpleNotificationService-0000000000000000000000.pem',
            'SubscribeURL': None,
            'Token': None,
            'TopicArn': 'arn',
            'Type': 'Notification',
            'MessageAttributes': {
                'attr1': {
                    'Type': 'String',
                    'Value': 'value1',
                }, 'attr2': {
                    'Type': 'String',
                    'Value': 'value2',
                }
            }
        }
        expected = json.dumps(msg)
        self.assertEqual(result, json.loads(expected))
    def test_create_sns_message_body_json_structure(self):