1 month 2 days and we switched to size 1 this week. The NB diapers were getting a little too small and most of all, couldn't contain his massive man-sized poo's anymore. The size 1 diapers are a little big, so I just roll down the front, similar to what we did when he still had the cord nub.
Side note: anyone notice that Huggies seem to run a bit smaller than Pampers? We use Pampers for A, but I bought a box of Huggies (by mistake, total PP brain). They seemed sooo small and A kept peeing out the side. Curious if the Huggies size 1 run small...we got a few boxes as gifts and I'd love to use them and save some $.