This hotfix adds the TZUtil command-line tool to Windows Vista and Windows Server 2008 operating systems. You can use the TZUtil command-line tool to change or verify the current time zone on a computer that is running Windows Vista or Windows Server 2008.
Note Windows stores the time zone database in the registry. Windows and other applications use this database to calculate local times. When time zone updates are available, Windows downloads the updates and then applies them to the database.