Parzival

Hello all I am trying to find the command Unraid uses to spin down and up disks so that I can add this to a bash script. My use case is that I know after a certain time my server will not be accessed for usually 12~ hours so I would like to spin down the drives at that time as there is no need for them to be up. Does anybody know what the command is as I've scoured the forum but have not found anything up to date that works.