Re: Y2k - Is Linux Ready for the year 2000?

Adam D. Bradley (artdodge@cs.bu.edu)
Mon, 5 Jan 1998 16:49:08 -0500 (EST)


> I need documentation concerning Linux's year 2000 compliancy, can anyone
> point me to it?

I don't know that you'll find much documentation, since Y2k is a
relative non-issue for most modern UNIX kernels. (See POSIX
1003.1b-1993, aka POSIX.4) It's primarily an issue for
poorly-written user applications and databases.

The kernel expresses dates using the UNIX epoch, i.e., a measure of
seconds since 00:00AM Jan 1 1970 GMT. Using a 32-bit signed
representation of seconds, the system clock will overflow sometime in
2038 (the Y2038 problem, don't hear much hype about that...guess it
just doesn't have a good "ring" to it, that and it's 40 years off),
using unsigned buys us another 68 years. Hopefully by then we'll all
be on 64-bit machines (at least), which won't overflow for another 290
or 580 billion years (approximate, signed vs unsigned). (I may be off
by a power of 2 on these, feel free to double-check me; I tend to not
care when dealing with timespans on the order of a star's life
expectancy.)

That's just the kernel; most well-written software will use the same
UNIX clock, but I'm sure there are some poorly written applications
out there (or applications with particular reasons for choosing
another date/time encoding) that will rollover before then. If you
need documentation of which individual applications are compliant, The
only way to check that is to ask the authors or read the source. GNU
can probably verify most of their stuff for you, but beyond that
you're really on your own... (the Linux Software Map can give you
e-mail addresses for lots of authors...)

Adam

--
Things look so bad everywhere      Adam D. Bradley      artdodge@cs.bu.edu
In this whole world what is fair        Boston University Computer Science
We walk blind and we try to see             Ph.D. student and Linux hacker
Falling behind in what could be  ---->  Bring me a Higher Love  ---->  <><