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


NAME

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


SYNOPSIS

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


DESCRIPTION

This module provides an interface for determining the local system's time zone. Most of the functionality for doing this is in OS-specific subclasses.


USAGE

This class provides the following methods:

DateTime::TimeZone::Locale->TimeZone()

This attempts to load an appropriate subclass and asks it to find the local time zone. This method is called by when you pass ``local'' as the time zone name to DateTime:TimeZone->new().

If an appropriate subclass does not exist, we fall back to using the Unix subclass.

See the DateTime::TimeZone::Local::Unix manpage, the DateTime::TimeZone::Local::Win32 manpage, and the DateTime::TimeZone::Local::VMS manpage for OS-specific details.


SUBCLASSING

If you want to make a new OS-specific subclass, there are several methods provided by this module you should know about.

$class->Methods()

This method should be provided by your class. It should provide a list of methods that will be called to try to determine the local time zone.

Each of these methods is expected to return a new DateTime::TimeZone object if it determines the time zone.

$class->FromEnv()

This method tries to find a valid time zone in an %ENV value. It calls $class->EnvVars() to determine which keys to look at.

To use this from a subclass, simply return ``FromEnv'' as one of the items from $class->Methods().

$class->EnvVars()

This method should be provided by your subclass. It should return a list of env vars to be checked by $class->FromEnv().

$class->_IsValidName($name)

Given a possible time zone name, this returns a boolean indicating whether or not the the name looks valid. It always return false for ``local'' in order to avoid infinite loops.


EXAMPLE SUBCLASS

Here is a simple example subclass:

  package DateTime::TimeZone::SomeOS;
  use strict;
  use warnings;
  use base 'DateTime::TimeZone::Local';
  sub Methods { qw( FromEnv FromEther ) }
  sub EnvVars { qw( TZ ZONE ) }
  sub FromEther
  {
      my $class = shift;
      ...
  }


AUTHOR

Dave Rolsky, <autarch@urth.org>


COPYRIGHT & LICENSE

Copyright (c) 2003-2007 David Rolsky. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

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

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