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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 query_map.items():
        if key.lower().startswith(OBJECT_METADATA_KEY_PREFIX):
            if headers.get(key) is None:
                headers[key] = value[0]
def fix_location_constraint(response):
    """ Make sure we return a valid non-empty LocationConstraint, as this otherwise breaks Serverless. """
    try:
        content = to_str(response.content or '') or ''
    except Exception:
        content = ''
    if 'LocationConstraint' in content:
        pattern = r'<LocationConstraint([^>]*)>\s*</LocationConstraint>'
        replace = r'<LocationConstraint\1>%s</LocationConstraint>' % aws_stack.get_region()
        response._content = re.sub(pattern, replace, content)
        remove_xml_preamble(response)
def fix_range_content_type(bucket_name, path, headers, response):
    
    if 'Range' not in headers:
        return
    s3_client = aws_stack.connect_to_service('s3')
    path = urlparse.unquote(path)
    key_name = get_key_name(path, headers)
    result = s3_client.head_object(Bucket=bucket_name, Key=key_name)
    content_type = result['ContentType']
    if response.headers.get('Content-Type') == 'text/html; charset=utf-8':
        response.headers['Content-Type'] = content_type
def fix_delete_objects_response(bucket_name, method, parsed_path, data, headers, response):