Something

on $*:text:/[!@`.]mute/Si:#:{ 
  if ($nick isop $chan || $nick ishop $chan || $nick == Yournickhere) { 
    set %dv $calc($3 * 60) 
    set %dv.chan $chan 
    set %dv.nick $2 
    mode $chan -vho %dv.nick %dv.nick %dv.nick 
    mode %dv.chan +m 
    notice %dv.nick You have been devoiced in %dv.chan for $3 minutes. 
    /timer2 1 %dv mode %dv.chan +v %dv.nick  
    /timer1 1 %dv notice $2 You have been re-voiced. 
    unset %dv 
    unset %dv.chan 
    unset %dv.nick
  } 
  else { 
    notice $nick You don't have permission to do that. 
  } 
}