It might be misreading your "null" as a negative number - epoch time is measured as the number of seconds from 1.1.1970 IIRC, and a lot of time values are stored in the database in epoch time values. I'd check the code but I'M ON VACATION! so maybe Aaron'll get bored later today and tell you.
Parts Unknown sent along this (slightly altered) image of collegiate sports and collegial atmosphere back in May. Those are some swell shirts those guys are wearing, but I'm pretty sure those are GANG SIGNS they're flashing.