def dt_get_timestamp(s, format="%Y-%m-%dT%H:%M:%S.%fZ"):
	ts = datetime.datetime.strptime(s, format)
	ts = ts.replace(tzinfo=pytz.UTC)
	ts = int(ts.timestamp() * 1000)
	return ts


def dt_get_isostring(ts, format='%Y-%m-%dT%H:%M:%S.%fZ'):
	s = datetime.datetime.utcfromtimestamp(ts / 1000.0).strftime(format)
	return s