I don't think it's necessarily a huge failing to not know about this/not teach your kid about it. Different kids have different curiosities, and as long as he i

I don't think it's necessarily a huge failing to not know about this/not teach your kid about it. Different kids have different curiosities, and as long as he is intellectually curious, and just didn't happen upon that particular calendrical oddity, then no biggie. However, I've seen some evidence that it is possible to do well at elite bay area schools without having much intellectual curiosity, and most teachers will give you high marks just for hard work and obedience. I'd say you are likely to come out ahead if you ignore elite status, and instead focus on whether teachers at your kids' schools nourish their intellectual curiosity.