# DateTime::TimeZone::Local::Unix - phpMan

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

## VERSION
    version 2.51

## 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:

    *   $ENV{TZ}

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

    *   /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.

    *   /etc/timezone

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

    *   /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.

    *   /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.

    *   /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) 2021 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.