Mine

on *:Text:brb*:#: {  msg $chan $nick will be away for a bit




  if (%gone. [ $+ [ $nick ] ] == $null) {
    set %gone. [ $+ [ $nick ] ] $ctime
  }
  else {
    halt
  }
}



on *:TEXT:back*:#: { 
  if (%gone. [ $+ [ $nick ] ] != $null) {
    notice $nick You've been away for  $duration($calc($ctime - %gone. [ $+ [ $nick ] ] $ctime))

    unset %gone. [ $+ [ $nick ] ]
    msg $chan *gives $nick a kiss* welcome back hun 
  }