sleep patterns with my newborn

I am new here but I have a question regarding my new little one.

My 6 week old is starting to sleep a little longer but currently he has his longest sleep from 6 pm - 11 pm.  I would like to change that to eventually be a little later at night but not quite sure how to do that.  He cluster feeds about 3 times from 3 - 6 pm then out like a light for 5 or more hours.  How do I start to change this to a later time each day.  I know I cant do it in one day but I would like to make it later and later each night until his long sleep is from 10 pm - 4 am.  

Any suggestions?  My pediatrician already said that the extended sleep is not harming him since he is gaining wait at a rapid rate.  He has gained about 4 lbs already which is much more than expected.

[peekawho]

Two schools of thought...I personally think either is acceptable.

1.  Just ride this out, and let your baby set the feeding times, pace, and length.  They are only newborns for such a little amount of time, and believe me...one day, you'll wish you had these days back, as hard and as tired as you are now.  There are many people who strongly believe that you should let the baby be your guide.

2.  You can try holding him off just by perhaps 15-20 minutes from some of those evening feeds, or try to get him up later in the evening again, if possible, for some awake time.  This might slowly change the pattern.

My personal feeling is that no matter what you do, the baby will eventually assume whatever feeding and sleep times he is tuned to, and there is very little to be done about it.  At 6 weeks, this is not set in stone.    I'd just go with the flow for now.  

Congrats on the baby!