presto-kinesis/src/main/java/io/prestosql/plugin/kinesis/KinesisSessionProperties.java/KinesisSessionProperties/getIteratorStartTimestamp
class KinesisSessionProperties:    public static long getIteratorStartTimestamp(ConnectorSession session)
    {
        String value = session.getProperty(STARTING_TIMESTAMP, String.class);
        if (value.equals(UNSET_TIMESTAMP)) {
            return 0;
        }
        return getTimestampAsMillis(value, session);
    }