DateTime::TimeZone::Local::Win32(3) Determine the local system's time zone on Windows


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 Windows platform.


This class tries the following methods of determining the local time zone:

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/''


Dave Rolsky, <[email protected]>


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.