When Jim and I were PK (pre-kids) we used to laugh at parents who gave their children’s ages in weeks or months. Jim thought it was ridiculous that a person would say “8 weeks” instead of 2 1/2 months …. or better yet …. why not just round it down or up to 2 or 3 months. And then …. there were the parents who’d say a child was 20 months. We’d…