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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?
import re
import logging
import json
import uuid
import base64
import codecs
import xmltodict
import collections
import botocore.config
import six
import datetime
import dateutil.parser
from six.moves.urllib import parse as urlparse
from botocore.client import ClientError
from requests.models import Response, Request
from localstack import config, constants
from localstack.config import HOSTNAME, HOSTNAME_EXTERNAL
from localstack.utils import persistence
from localstack.utils.aws import aws_stack
from localstack.utils.common import (
    short_uid, timestamp, TIMESTAMP_FORMAT_MILLIS, to_str, to_bytes, clone, md5, get_service_protocol)
from localstack.utils.analytics import event_publisher
from localstack.utils.aws.aws_responses import requests_response
from localstack.services.s3 import multipart_content
from localstack.services.generic_proxy import ProxyListener
CONTENT_SHA256_HEADER = 'x-amz-content-sha256'
STREAMING_HMAC_PAYLOAD = 'STREAMING-AWS4-HMAC-SHA256-PAYLOAD'
S3_NOTIFICATIONS = {}
BUCKET_CORS = {}