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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?
for key, value in sub.items():
                    content += '<entry><key>%s</key><value>%s</value></entry>\n' % (key, value)
                content += '</Attributes>'
                return make_response(req_action, content=content)
            elif req_action == 'Subscribe':
                if 'Endpoint' not in req_data:
                    return make_error(message='Endpoint not specified in subscription', code=400)
            elif req_action == 'ConfirmSubscription':
                if 'TopicArn' not in req_data:
                    return make_error(message='TopicArn not specified in confirm subscription request', code=400)
                if 'Token' not in req_data:
                    return make_error(message='Token not specified in confirm subscription request', code=400)
                do_confirm_subscription(req_data.get('TopicArn')[0], req_data.get('Token')[0])
            elif req_action == 'Unsubscribe':
                if 'SubscriptionArn' not in req_data:
                    return make_error(message='SubscriptionArn not specified in unsubscribe request', code=400)
                do_unsubscribe(req_data.get('SubscriptionArn')[0])
            elif req_action == 'DeleteTopic':
                do_delete_topic(topic_arn)
            elif req_action == 'Publish':
                if req_data.get('Subject') == ['']:
                    return make_error(code=400, code_string='InvalidParameter', message='Subject')
                
                
                if 'PhoneNumber' not in req_data and 'TargetArn' not in req_data:
                    if topic_arn not in SNS_SUBSCRIPTIONS.keys():
                        return make_error(code=404, code_string='NotFound', message='Topic does not exist')
                    publish_message(topic_arn, req_data)
                
                return make_response(req_action)