As long as you're feeding on cue, not over using a paci, baby is wetting/soiling enough, and baby is gaining well, I wouldn't worry about how long he goes between feedings day or night.
My DS probably eats every 2hours or so during the day, but will go much long at night sometimes (not entirely sure b/c we cosleep and don't have to change dipes at night very much). Last night, I only remeber nursing him for a long time before he fell asleep at around 8, then again at midnight, and once more at 6 am. If I fed him between midnight and 6, I don't remember it. LOL. I would jump for joy if this one started sleeping "through the night" so early. DD didn't sleep throught the night by the medical definition for at least 2 years, then not completely through the night until several months ago (she turned 3 June 21).