Systems running Unix or Unix-like operating systems are likely to be OK with the changeover to 2000, but they may have problems in 2038. You see, the system time in Unix is represented internally by the number of seconds since the so-called epoch time, which occurred at the very beginning of 1970. The number of seconds from the epoch is typically (invariably?) represented by a signed 32-bit integer, which means that the system time will overflow 2 147 483 648 seconds after the epoch.
As it happens, this overflow will occur on 2038-01-19 (a Tuesday) at 03:14:08 UTC, so the system time will go from 2038-01-19 03:14:07 UTC to 1901-12-13 20:45:52 UTC.
Furthermore, on Unix systems that store dates in UTC internally (are there any that don't?), this incorrect rollover will occur at the same time around the world. This differs from many types of year-2000 problem, which are dependent on the local time, giving a little extra time to solve problems after they been discovered elsewhere in the world.
While we're on the topic, why don't I encourage you to start using the ANSI/ISO date format?
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