DateTime::TimeZone::Local::Unix − Determine the local system’s time zone on Unix
version 2.35
my $tz =
DateTime::TimeZone−>new( name => 'local' );
my $tz = DateTime::TimeZone::Local−>TimeZone();
This module provides methods for determining the local time zone on a Unix platform.
This class tries the following methods of determining the local time zone:
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$ENV{ TZ } |
It checks $ENV{TZ} for a valid time zone name.
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/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.
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/etc/timezone |
If this file exists, it is read and its contents are used as a time zone name.
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/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.
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/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.
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/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.
Bugs may be submitted at <https://github.com/houseabsolute/DateTime−TimeZone/issues>.
I am also usually active on IRC as ’autarch’ on "irc://irc.perl.org".
The source code repository for DateTime-TimeZone can be found at <https://github.com/houseabsolute/DateTime−TimeZone>.
Dave Rolsky <autarch@urth.org>
This software is copyright (c) 2019 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.