not working script

Get-ChildItem g:\old*.mp4 -Recurse | foreach {
$x = $_.LastWriteTime.ToShortDateString()
$new_folder_name = Get-Date $x -Format yyyy.MM.dd
$des_path = "g:\old\$new_folder_name"

if (test-path $des_path){
    move-item $_.fullname $des_path
    } else {
    new-item -ItemType directory -Path $des_path
    move-item $_.fullname $des_path
    }
}
pause