DateTime::TimeZone::Local::Unix(3)         User Contributed Perl Documentation


NAME
       DateTime::TimeZone::Local::Unix - Determine the local system's time
       zone on Unix

VERSION
       version 2.62

SYNOPSIS
         my $tz = DateTime::TimeZone->new( name => 'local' );

         my $tz = DateTime::TimeZone::Local->TimeZone();

DESCRIPTION
       This module provides methods for determining the local time zone on a
       Unix platform.

HOW THE TIME ZONE IS DETERMINED
       This class tries the following methods of determining the local time
       zone:

       o   $ENV{TZ}

           It checks $ENV{TZ} for a valid time zone name.

       o   /etc/localtime

           If this file is a symlink to an Olson database time zone file
           (usually in /usr/share/zoneinfo) then it uses the target file's
           path name to determine the time zone name. For example, if the path
           is /usr/share/zoneinfo/America/Chicago, the time zone is
           "America/Chicago".

           Some systems just copy the relevant file to /etc/localtime instead
           of making a symlink.  In this case, we look in /usr/share/zoneinfo
           for a file that has the same size and content as /etc/localtime to
           determine the local time zone.

       o   /etc/timezone

           If this file exists, it is read and its contents are used as a time
           zone name.

       o   /etc/TIMEZONE

           If this file exists, it is opened and we look for a line starting
           like "TZ = ...". If this is found, it should indicate a time zone
           name.

       o   /etc/sysconfig/clock

           If this file exists, it is opened and we look for a line starting
           like "TIMEZONE = ..." or "ZONE = ...". If this is found, it should
           indicate a time zone name.

       o   /etc/default/init

           If this file exists, it is opened and we look for a line starting
           like "TZ=...". If this is found, it should indicate a time zone
           name.

       Note: Some systems such as virtual machine boxes may lack any of these
       files. You can confirm that this is case by running:

           $ ls -l /etc/localtime /etc/timezone /etc/TIMEZONE \
               /etc/sysconfig/clock /etc/default/init

       If this is the case, then when checking for timezone handling you are
       likely to get an exception:

           $ perl -wle 'use DateTime; DateTime->now( time_zone => "local" )'
           Cannot determine local time zone

       In that case, you should consult your system man pages for details on
       how to address that problem. In one such case reported to us, a FreeBSD
       virtual machine had been built without any of these files. The user was
       able to run the FreeBSD tzsetup utility. That installed /etc/localtime,
       after which the above timezone diagnostic ran silently, i.e., without
       throwing an exception.

SUPPORT
       Bugs may be submitted at
       <https://github.com/houseabsolute/DateTime-TimeZone/issues>.

SOURCE
       The source code repository for DateTime-TimeZone can be found at
       <https://github.com/houseabsolute/DateTime-TimeZone>.

AUTHOR
       Dave Rolsky <autarch@urth.org>

COPYRIGHT AND LICENSE
       This software is copyright (c) 2024 by Dave Rolsky.

       This is free software; you can redistribute it and/or modify it under
       the same terms as the Perl 5 programming language system itself.

       The full text of the license can be found in the LICENSE file included
       with this distribution.

perl v5.38.1                      2024-02-07
                                            DateTime::TimeZone::Local::Unix(3)