Description

Getting time zone information in PowerShell is an exercise in simplicity. This single command:

PowerShell
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[TimeZoneInfo]::Local
 

... yields about as much information as you’d generally care to know about the current system time zone. 

Sample results:

Id                         : Mountain Standard Time
DisplayName                : (UTC-07:00) Mountain Time (US & Canada)
StandardName               : Mountain Standard Time
DaylightName               : Mountain Daylight Time
BaseUtcOffset              : -07:00:00
SupportsDaylightSavingTime : True

Setting the current time zone, unfortunately, isn’t quite as easy or intuitive. This is something I needed to do a while back for my desktop imaging process. Although the runtime portion of the Microsoft Deployment Tools (MDT) are largely built on a VBScript foundation, most of my deployment scripts are PowerShell-based, so I came up with a simple Posh function for setting the system time zone that works for both Windows XP and Windows 7.

There are a number of crazy ways to set time zone information, but rather than delving into methods that directly modify the registry and such, I decided upon documented, supported ways to change the current time zone.

You can call this function using the friendly time zone name associated with the zone you want. For example,

Set-TimeZone "Pacific Standard Time"
Set-TimeZone "North Asia East Standard Time"
Set-TimeZone "GMT Standard Time"

… and so on.

Note that the function uses the .NET Process class to execute the necessary commands. The Windows 7 tzutil method doesn’t need this, but the control.exe command used for XP and earlier won’t work with the Start-Process cmdlet, so I went with the lowest common denominator.

 

Script

PowerShell
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function Set-TimeZone { 
 
    param( 
        [parameter(Mandatory=$true)] 
        [string]$TimeZone 
    ) 
     
    $osVersion = (Get-Item "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion").GetValue("CurrentVersion") 
    $proc = New-Object System.Diagnostics.Process 
    $proc.StartInfo.WindowStyle = "Hidden" 
 
    if ($osVersion -ge 6.0) 
    { 
        # OS is newer than XP 
        $proc.StartInfo.FileName = "tzutil.exe" 
        $proc.StartInfo.Arguments = "/s `"$TimeZone`"" 
    } 
    else 
    { 
        # XP or earlier 
        $proc.StartInfo.FileName = $env:comspec 
        $proc.StartInfo.Arguments = "/c start /min control.exe TIMEDATE.CPL,,/z $TimeZone" 
    } 
 
    $proc.Start() | Out-Null 
 
}