For when you want to easily schedule a local shutdown. e.g. a windows sleep timer. This is a simple UI to assist.

PowerShell Local Shutdown.ps1

[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Drawing") 
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms") 

$objForm = New-Object System.Windows.Forms.Form 
$objForm.Text = "Shutdown Timer"
$objForm.Size = New-Object System.Drawing.Size(300,200) 
$objForm.StartPosition = "CenterScreen"

$objForm.KeyPreview = $True
$objForm.Add_KeyDown({if ($_.KeyCode -eq "Enter") 
    {$x=$objTextBox.Text;$objForm.Close()}})
$objForm.Add_KeyDown({if ($_.KeyCode -eq "Escape") 
    {$objForm.Close()}})

$OKButton = New-Object System.Windows.Forms.Button
$OKButton.Location = New-Object System.Drawing.Size(100,120)
$OKButton.Size = New-Object System.Drawing.Size(75,23)
$OKButton.Text = "Set Timer"
$OKButton.Add_Click({$x=$objTextBox.Text;$objForm.Close()})
$objForm.Controls.Add($OKButton)

$objLabel = New-Object System.Windows.Forms.Label
$objLabel.Location = New-Object System.Drawing.Size(10,20) 
$objLabel.Size = New-Object System.Drawing.Size(280,40) 
$objLabel.Text = "Shutdown in how many minutes? (type 'cancel' to stop a pending timer)"
$objForm.Controls.Add($objLabel) 

$objTextBox = New-Object System.Windows.Forms.TextBox 
$objTextBox.Location = New-Object System.Drawing.Size(10,60) 
$objTextBox.Size = New-Object System.Drawing.Size(260,20) 
$objForm.Controls.Add($objTextBox) 

$objForm.Topmost = $True

$objForm.Add_Shown({$objForm.Activate()})
[void] $objForm.ShowDialog()

$tool="shutdown"

if($x -eq 'cancel'){
  $cmdLine = "-a"
  invoke-expression "$tool $cmdLine"
}
elseif($x -match '^\d+$'){
  $secondsTilShutdown = [System.Convert]::ToInt32($x) * 60
  $cmdLine = "-s -t $secondsTilShutdown -f"
  invoke-expression "$tool $cmdLine"
}