1The following information about Perl and the year 2000 is a modified
2version of the information that can be found in the Frequently Asked
3Question (FAQ) documents.
4
5Does Perl have a year 2000 problem?  Is Perl Y2K compliant?
6
7Short answer: No, Perl does not have a year 2000 problem.  Yes,
8       Perl is Y2K compliant (whatever that means).  The
9       programmers you've hired to use it, however, probably are
10       not.  If you want perl to complain when your programmers
11       create programs with certain types of possible year 2000
12       problems, a build option allows you to turn on warnings.
13
14Long answer: The question belies a true understanding of the
15       issue.  Perl is just as Y2K compliant as your pencil
16       --no more, and no less.  Can you use your pencil to write
17       a non-Y2K-compliant memo?  Of course you can.  Is that
18       the pencil's fault?  Of course it isn't.
19
20       The date and time functions supplied with perl (gmtime and
21       localtime) supply adequate information to determine the
22       year well beyond 2000 (2038 is when trouble strikes for
23       32-bit machines).  The year returned by these functions
24       when used in a list context is the year minus 1900.  For
25       years between 1910 and 1999 this happens to be a 2-digit
26       decimal number. To avoid the year 2000 problem simply do
27       not treat the year as a 2-digit number.  It isn't.
28
29       When gmtime() and localtime() are used in scalar context
30       they return a timestamp string that contains a fully-
31       expanded year.  For example, $timestamp =
32       gmtime(1005613200) sets $timestamp to "Tue Nov 13 01:00:00
33       2001".  There's no year 2000 problem here.
34
35       That doesn't mean that Perl can't be used to create non-
36       Y2K compliant programs.  It can.  But so can your pencil.
37       It's the fault of the user, not the language.  At the risk
38       of inflaming the NRA: ``Perl doesn't break Y2K, people
39       do.''  See http://language.perl.com/news/y2k.html for a
40       longer exposition.
41
42       If you want perl to warn you when it sees a program which
43       concatenates a number with the string "19" -- a common
44       indication of a year 2000 problem -- build perl using the
45       Configure option  "-Accflags=-DPERL_Y2KWARN".
46       (See the file INSTALL for more information about building
47       perl.)
48