Hi there! I'm no expert but my lo is about the same age. I started feeding him later and later because he was just playing with the bottel at 3 hrs, and adjusted his naps accoedingly. 1hr20 mins A time sounds right. Mine is only now, ar 16 weeks, slowly having longer A times, like 5 mins longer!! Also, is your lo perhaps on a griwth spurt? If so, you can give him the extra ounces an hour after the feed. Hth!