LinuxPlanet: Y2K and Linux

“The good news is that by and large, Linux and all other members
of the Unix family tree are immune to the Y2K problem, since they
keep track of time internally in way that’s different from that
described above. Instead of storing a month, a day, and a year as
separate pieces of information, they simply keep a count of the
seconds since January 1, 1970, and convert this to a more
user-friendly format, as needed…such as when displaying the date
a file was last changed. Even better is the news that the vast
majority of Linux programs use this same method for representing
dates, probably because it was easiest to simply follow the
operating system’s lead, so they’ll also breeze right past 1/1/2000
with nary a hiccup.”

“This doesn’t mean, however, that Linux doesn’t have its own
data issues. Because that counter Linux uses to store the number of
seconds since 1/1/1970 can only hold a number so large (it’s a
32-bit binary number, in fact), it will hit its upper limit and
wrap around, much like the odometer on a car will go from all 9’s
to all 0’s. This won’t happen on Linux and other Unix variants
until January of 2038, so we all have considerable breathing room.
More important, long before 2038 we will have moved well beyond
today’s 32-bit systems, and Linux will very likely be changed to
use a larger number to store that count of seconds. The next likely
size is 64 bits, which will give us a counter so absurdly large it
won’t wrap around until sometime after the sun burns out.