1DateTime::TimeZone::LocUasle:r:UCnoinxt(r3i)buted Perl DDoactuemTeinmtea:t:iToinmeZone::Local::Unix(3)
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NAME

6       DateTime::TimeZone::Local::Unix - Determine the local system's time
7       zone on Unix
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VERSION

10       version 2.60
11

SYNOPSIS

13         my $tz = DateTime::TimeZone->new( name => 'local' );
14
15         my $tz = DateTime::TimeZone::Local->TimeZone();
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DESCRIPTION

18       This module provides methods for determining the local time zone on a
19       Unix platform.
20

HOW THE TIME ZONE IS DETERMINED

22       This class tries the following methods of determining the local time
23       zone:
24
25       •   $ENV{TZ}
26
27           It checks $ENV{TZ} for a valid time zone name.
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29       •   /etc/localtime
30
31           If this file is a symlink to an Olson database time zone file
32           (usually in /usr/share/zoneinfo) then it uses the target file's
33           path name to determine the time zone name. For example, if the path
34           is /usr/share/zoneinfo/America/Chicago, the time zone is
35           "America/Chicago".
36
37           Some systems just copy the relevant file to /etc/localtime instead
38           of making a symlink.  In this case, we look in /usr/share/zoneinfo
39           for a file that has the same size and content as /etc/localtime to
40           determine the local time zone.
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42       •   /etc/timezone
43
44           If this file exists, it is read and its contents are used as a time
45           zone name.
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47       •   /etc/TIMEZONE
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49           If this file exists, it is opened and we look for a line starting
50           like "TZ = ...". If this is found, it should indicate a time zone
51           name.
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53       •   /etc/sysconfig/clock
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55           If this file exists, it is opened and we look for a line starting
56           like "TIMEZONE = ..." or "ZONE = ...". If this is found, it should
57           indicate a time zone name.
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59       •   /etc/default/init
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61           If this file exists, it is opened and we look for a line starting
62           like "TZ=...". If this is found, it should indicate a time zone
63           name.
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65       •   /etc/localtime content
66
67           If this file is not a symlink, it's parsed by a
68           DateTime::TimeZone::Tzfile to retrieve the time zone offset
69           definition. No time zone name will be defined. This is usefull if
70           the file does not present in the system time zone database.
71
72       Note: Some systems such as virtual machine boxes may lack any of these
73       files. You can confirm that this is case by running:
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75           $ ls -l /etc/localtime /etc/timezone /etc/TIMEZONE \
76               /etc/sysconfig/clock /etc/default/init
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78       If this is the case, then when checking for timezone handling you are
79       likely to get an exception:
80
81           $ perl -wle 'use DateTime; DateTime->now( time_zone => "local" )'
82           Cannot determine local time zone
83
84       In that case, you should consult your system man pages for details on
85       how to address that problem. In one such case reported to us, a FreeBSD
86       virtual machine had been built without any of these files. The user was
87       able to run the FreeBSD tzsetup utility. That installed /etc/localtime,
88       after which the above timezone diagnostic ran silently, i.e., without
89       throwing an exception.
90

SUPPORT

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

96       The source code repository for DateTime-TimeZone can be found at
97       <https://github.com/houseabsolute/DateTime-TimeZone>.
98

AUTHOR

100       Dave Rolsky <autarch@urth.org>
101

103       This software is copyright (c) 2023 by Dave Rolsky.
104
105       This is free software; you can redistribute it and/or modify it under
106       the same terms as the Perl 5 programming language system itself.
107
108       The full text of the license can be found in the LICENSE file included
109       with this distribution.
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113perl v5.36.0                      2023-03-29DateTime::TimeZone::Local::Unix(3)
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