my daughter is eight weeks old and she does the same. she sleeps from 6pm - 6am with no feed, but every two hours during the day... i was told that it was because they still need the same quantity of food so they feed more often during the day to make up for the long stint with no food at night. sometimes my daughter will go from 9am - 6pm with just a few cat naps. she is also taking a lot more formula at every feed than she used to when she had night feeds.... as for the screaming, don't know sorry. maybe he is just not tired so does not want to go to bed? hope this helps...