DateTime::TimeZone::Local::Win32(3)

NAME
DateTime::TimeZone::Local::Win32 - Determine the local system's time zone on Windows

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 Windows 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.

•   Windows Registry

    When using the registry, we look for the Windows time zone and use a mapping to translate this to an Olson time zone name.

    •   Windows Vista and 2008

        We look in "SYSTEM/CurrentControlSet/Control/TimeZoneInformation/" for a node named "/TimeZoneKeyName". If this exists, we use this key to look up the Olson time zone name in our mapping.

    •   Windows NT, Windows 2000, Windows XP, Windows 2003 Server

        We look in "SOFTWARE/Microsoft/Windows NT/CurrentVersion/Time Zones/" and loop through all of its sub keys.

        For each sub key, we compare the value of the key with "/Std" appended to the end to the value of "SYSTEM/CurrentControlSet/Control/TimeZoneInformation/StandardName". This gives us the English name of the Windows time zone, which we use to look up the Olson time zone name.

    •   Windows 95, Windows 98, Windows Millenium Edition

        The algorithm is the same as for NT, but we loop through the sub keys of "SOFTWARE/Microsoft/Windows/CurrentVersion/Time Zones/"

AUTHOR
Dave Rolsky, <autarch@urth.org>

COPYRIGHT & LICENSE
Copyright (c) 2003-2008 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.