Time::y2038(3pm)
NAME
Time::y2038 - Versions of Perl's time functions which work beyond 2038
SYNOPSIS
use Time::y2038; print scalar gmtime 2**52; # Sat Dec 6 03:48:16 142715360
DESCRIPTION
On many computers, Perl's time functions will not work past the year
2038. This is a design fault in the underlying C libraries Perl uses.
Time::y2038 provides replacements for those functions which will work
accurately +/1 142 million years.
This only imports the functions into your namespace. To replace it
everywhere, see Time::y2038::Everywhere.
Replaces the following functions:
gmtime()
See "gmtime" in perlfunc for details.
localtime()
See "localtime" in perlfunc for details.
- timegm()
- my $time = timegm($sec, $min, $hour, $month_day, $month, $year);
- The inverse of "gmtime()", takes a date and returns the coorsponding
$time (number of seconds since Midnight, January 1st, 1970 GMT). All
values are the same as "gmtime()" so $month is 0..11 (January is 0) and the $year is years since 1900 (2008 is 108).
# June 4, 1906 03:02:01 GMT
my $time = timegm(1, 2, 3, 4, 5, 6);timegm() can take two additional arguments which are always ignored. This lets you feed the results from gmtime() back into timegm() without having to strip the arguments off.The following is always true:
timegm(gmtime($time)) == $time;timelocal()
my $time = timelocal($sec, $min, $hour, $mday, $month, $year);
my $time = timelocal($sec, $min, $hour, $mday, $month, $year, $wday, $yday, $isdst);Like "timegm()", but interprets the date in the current time zone."timelocal()" will normally figure out if daylight savings time is in
effect, but if $isdst is given this will override that check. This is mostly useful to resolve ambiguous times around "fall back" when the
hour between 1am and 2am occurs twice.
# Sun Nov 4 00:59:59 2007
print timelocal(59, 59, 0, 4, 10, 107); # 1194163199# Sun Nov 4 01:00:00 2007 DST, one second later
print timelocal(0, 0, 1, 4, 10, 107, undef, undef, 1); # 1194163200# Sun Nov 4 01:00:00 2007 no DST, one hour later
print timelocal(0, 0, 1, 4, 10, 107, undef, undef, 0); # 1194166800$wday and $yday are ignored. They are only there for compatibility
with the return value of "localtime()".
LIMITATIONS
The safe range of times is +/ 2**52 (about 142 million years).
Although the underlying time library can handle times from -2**63 to
2**63-1 (about +/- 292 billion years) Perl uses floating point numbers
internally and so accuracy degrates after 2**52.
BUGS & FEEDBACK
See http://rt.cpan.org/Dist/Display.html?Queue=Time-y2038 to report and
view bugs.
If you like the module, please drop the author an email.
The latest version of this module can be found at
http://y2038.googlecode.com/ and the repository is at
http://y2038.googlecode.com/svn/trunk/ in perl/Time-y2038. You have to
check out the whole repository because there are symlinks.
AUTHOR
Michael G Schwern <schwern@pobox.com>
LICENSE & COPYRIGHT
Copyright 2008-2010 Michael G Schwern
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
See http://www.perl.com/perl/misc/Artistic.html
SEE ALSO
Time::y2038::Everywhere overrides localtime() and gmtime() across the
whole program.
The y2038 project at http://y2038.googlecode.com/
- <http://xkcd.com/376/>