Waking a sleeping baby

Dolls2011

I know, I know... Never wake a sleeping baby but my 11 week old keeps falling asleep after his 6pm feeding and staying asleep until about midnight to 1am, when he wakes up to eat. I would like him to eat at a later time, preferably 9ish, so that he'll sleep longer through the night. So, should I start waking him at 9 to eat again or just leave him be?