PhilW
It was probably one of those instances where the number of seconds since 1970 overflows the type of variable that was used to store it, I think it's 32-bits. There's even a somewhat tongue-in-cheek website 2038.org that talks about it.
Yup basically.
So behind the scenes - "lifetime" is actually 100 years. When a lifetime order came through we stamped it for 100 years. The problem was that SONAR (at the time we rolled out lifetime updates, it has since been fixed) was using unix time (or elapsed seconds since 1/1/1970) stored as a 32-bit integer. So when auth passed SONAR a date for the year 2116 it was displaying as 1980-something since it overflowed. To fix this we were only reporting out to 2037. SONAR supports any date now but we haven't gotten around to changing the reporting - in the next few months once the share of users is well past those older versions we'll probably take off the safety valve.
If you believe that you'll live beyond 2116, drop us a note around 2114 or so and we'll bump your date out.