[Amail]

I'm with the cook.

1/1/2001
2/2/2004
3/3/2009
4/4/2016
5/5/2025
6/6/2036
7/7/2049
8/8/2068
9/9/2081

According to Wikipedia (and they're never wrong ;-)), this happens 9 times a century and is attributed to a science teacher back in 1981.