During the interview Theo de Raadt mentioned his keynote speech at EuroBSDCon where he talked about the conversion of OpenBSD to 64-bit (long long) time_t for both 32-bit and the 64-bit systems because of the Y2K38 problem.
http://www.openbsd.org/papers/eurobs...e_t/index.html
FreeBSD and Linux converted to 64-bit dates by using the plain "long" datatype which is 64-bits on 64-bit systems.
But as Theo points out,
32-bit POSIX systems are all broken, because the long datatype is 32-bits long on 32-bit systems.
32-bit systems are in wide use but they are not safe such as this nuclear power plant still using PDP-11 code:
http://www.openbsd.org/papers/eurobs.../mgp00014.html