Time::y2038(3pm)

1Time::y2038(3)        User Contributed Perl Documentation       Time::y2038(3)
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NAME

6       Time::y2038 - Versions of Perl's time functions which work beyond 2038
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SYNOPSIS

9           use Time::y2038;
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11           print scalar gmtime 2**52;  # Sat Dec  6 03:48:16 142715360
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DESCRIPTION

14       On many computers, Perl's time functions will not work past the year
15       2038.  This is a design fault in the underlying C libraries Perl uses.
16       Time::y2038 provides replacements for those functions which will work
17       accurately +/1 142 million years.
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19       This only imports the functions into your namespace.  To replace it
20       everywhere, see Time::y2038::Everywhere.
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22       Replaces the following functions:
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24       gmtime()
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26       See "gmtime" in perlfunc for details.
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28       localtime()
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30       See "localtime" in perlfunc for details.
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32       timegm()
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34           my $time = timegm($sec, $min, $hour, $month_day, $month, $year);
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36       The inverse of "gmtime()", takes a date and returns the coorsponding
37       $time (number of seconds since Midnight, January 1st, 1970 GMT).  All
38       values are the same as "gmtime()" so $month is 0..11 (January is 0) and
39       the $year is years since 1900 (2008 is 108).
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41           # June 4, 1906 03:02:01 GMT
42           my $time = timegm(1, 2, 3, 4, 5, 6);
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44       timegm() can take two additional arguments which are always ignored.
45       This lets you feed the results from gmtime() back into timegm() without
46       having to strip the arguments off.
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48       The following is always true:
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50           timegm(gmtime($time)) == $time;
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52       timelocal()
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54           my $time = timelocal($sec, $min, $hour, $mday, $month, $year);
55           my $time = timelocal($sec, $min, $hour, $mday, $month, $year, $wday, $yday, $isdst);
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57       Like "timegm()", but interprets the date in the current time zone.
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59       "timelocal()" will normally figure out if daylight savings time is in
60       effect, but if $isdst is given this will override that check.  This is
61       mostly useful to resolve ambiguous times around "fall back" when the
62       hour between 1am and 2am occurs twice.
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64           # Sun Nov  4 00:59:59 2007
65           print timelocal(59, 59, 0, 4, 10, 107);  # 1194163199
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67           # Sun Nov  4 01:00:00 2007 DST, one second later
68           print timelocal(0, 0, 1, 4, 10, 107, undef, undef, 1);  # 1194163200
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70           # Sun Nov  4 01:00:00 2007 no DST, one hour later
71           print timelocal(0, 0, 1, 4, 10, 107, undef, undef, 0);  # 1194166800
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73       $wday and $yday are ignored.  They are only there for compatibility
74       with the return value of "localtime()".
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LIMITATIONS

77       The safe range of times is +/ 2**52 (about 142 million years).
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79       Although the underlying time library can handle times from -2**63 to
80       2**63-1 (about +/- 292 billion years) Perl uses floating point numbers
81       internally and so accuracy degrates after 2**52.
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BUGS & FEEDBACK

84       See http://rt.cpan.org/Dist/Display.html?Queue=Time-y2038 to report and
85       view bugs.
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87       If you like the module, please drop the author an email.
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89       The latest version of this module can be found at
90       http://y2038.googlecode.com/ and the repository is at
91       http://y2038.googlecode.com/svn/trunk/ in perl/Time-y2038.  You have to
92       check out the whole repository because there are symlinks.
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AUTHOR

95       Michael G Schwern <schwern@pobox.com>
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LICENSE & COPYRIGHT

98       Copyright 2008-2010 Michael G Schwern
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100       This program is free software; you can redistribute it and/or modify it
101       under the same terms as Perl itself.
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103       See http://www.perl.com/perl/misc/Artistic.html
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