Once I'm done washing my eyeballs, I realize I saw something interesting. Many, many spam emails have the date "1/1/38" aka January 1, 2038 (which, by the way, is a Monday). I realize they have the future date so they're the latest emails, but why that date?
Being a nerd, I figured it has something to do with the maximal value of the "date" field on an email and how time is measured on computer systems (from a fixed date in the past like Jan 1, 1970).
Turns out that, according to the Intertubes, I'm right. It's the largest date representable with using the 32-bit time value. There's even an associated problem (like Y2K), called the Year 2038 problem (Wikipedia).
And there you go. Wonder no more.