PowerShell script to lower monitor brightness

Limit-MonitorBrightness.ps1

[CmdletBinding()]
param (
    [Parameter()]
    [string]
    $TimeFrom = '17:00',
    
    [string]
    $TimeTo = '20:00'
)


Set-StrictMode -Version Latest

[DateTime]$datetimeFrom = Get-Date $TimeFrom
[DateTime]$datetimeTo = Get-Date $TimeTo

Write-Verbose "`$datetimeFrom.ToString() = $($datetimeFrom.ToString())"
Write-Verbose "`$datetimeTo.ToString()   = $($datetimeTo.ToString())"

[int]$duration = ($datetimeTo - $datetimeFrom).TotalSeconds
Write-Verbose "`$duration = $($duration)"

$wmiMonitorBrightnessMethodsInstance = Get-CimInstance -Namespace root/wmi -ClassName WmiMonitorBrightnessMethods

[int]$timeout = 5
[int]$waitSecond = 1

while ($true) {
    
    if ((Get-Date) -ge $datetimeFrom) {
        
        [int]$passedSeconds = ((Get-Date) - $datetimeFrom).TotalSeconds
        
        $wmiMonitorBrightnessInstance = Get-CimInstance -Namespace root/wmi -ClassName WmiMonitorBrightness
        
        [int]$brightnessAsIs = $wmiMonitorBrightnessInstance.CurrentBrightness
        [int]$brightnessToBe = [int](100 - ($passedSeconds / $duration * 100))
        
        Write-Verbose "`$passedSeconds  = $($passedSeconds)"
        Write-Verbose "`$brightnessAsIs = $($brightnessAsIs)"
        Write-Verbose "`$brightnessToBe = $($brightnessToBe)"

        if ($brightnessToBe -lt 0) {
            $brightnessToBe = 0
        }

        if ($brightnessAsIs -gt $brightnessToBe) {
            $wmiMonitorBrightnessMethodsInstance | 
                Invoke-CimMethod -MethodName WmiSetBrightness -Arguments @{Brightness = $brightnessToBe; Timeout = $timeout;} | 
                Out-Null
        }
    }
    
    Start-Sleep -Seconds $waitSecond
}