Another PowerShell egg-timer (using events)

gistfile1.ps1

<# 
.SYNOPSIS 
    This script provides simple egg-timer like functionality. 
    
.DESCRIPTION 
    This script counts down a time interval then speaks some text
        
.NOTES 
    File Name  : Run-Timer.ps1 
    Requires   : PowerShell Version 2.0
    
.PARAMETER Minutes

Delay in minutes

.PARAMETER Seconds

Additional delay in seconds

.PARAMETER Text

What to say at the end of the time

.PARAMETER Help

Show this help text.
#>
param ( 
    [ValidateRange(0,59)] [int] $Minutes,
    [ValidateRange(0,59)] [int] $Seconds,
    [string] $Text="It is time",
    [switch] $Help)

if ($help)
{
    Get-Help $MyInvocation.MyCommand.Definition
    return
}

$delay = new-object "system.timespan" @(0, $Minutes, $Seconds)
$fireAt = [System.DateTime]::UtcNow + $delay
Write-Host "Requested alarm time = `t$fireAt"

# Do the heavy lifting up front
$Voice = new-object -com SAPI.SpVoice
$Voice.Rate = -5
$timer = new-object "system.timers.timer" @(250.0)
$timer.autoreset = $true

$handler =  {
    # extract arguments (no closures here)
    $fireAt = $Event.MessageData
    $timer = $Sender
  
    # round time to wait to integer seconds and display
    $delta = $fireAt - [System.DateTime]::UtcNow
    $delta = new-object "system.timespan" @(0, $delta.Minutes, [System.Math]::Round($delta.Seconds))
    [System.Console]::Write("$delta`r")
  
    # After the time allotted, kill the timer
    if ([System.DateTime]::UtcNow -gt $fireAt) { 
        $timer.enabled = $false
        $timer.autoreset = $false
        $timer.Dispose() 
    }
}

Register-ObjectEvent -InputObject $timer -EventName Elapsed -SourceIdentifier "Timer.Elapsed" -Action $handler -MessageData $fireAt | Out-Null
Register-ObjectEvent -InputObject $timer -EventName Disposed -SourceIdentifier "Timer.Disposed"

$timer.Start() 

# Wait until done
if (-not (Wait-Event "Timer.Disposed" -Timeout 3600 )) {
    Write-Host "Timed out"
    $timer.Stop() 
    $timer.Dispose()
} else {
    Write-Host "Completed"
}
Write-Host "Actual alarm time = `t$([System.DateTime]::UtcNow)"

# Tidy event registrations and event queue
# The Elapsed events are spent in the handler
# but the one we wait on must be explicitly cleared
Remove-Event "Timer.Disposed"
Unregister-Event "Timer.Elapsed"
Unregister-Event "Timer.Disposed"

#audible alarm
$Voice.Speak($Text) | Out-Null
Write-Host "`r`nDone"