on $*:TEXT:/^(brb|bbl|bbs)/Si:#:{  
  set %away [ $+ [ $chan ] ] $2-
  set %time [ $+ [ $chan ] ] $ctime
  set %nick [ $+ [ $chan ] ] $nick
  msg $chan 14[[7-Away-14]]4 %nick [ $+ [ $chan ] ] 12Is now away, Reason:4 %away [ $+ [ $chan ] ] $+ 12.4 %nick [ $+ [ $chan ] ] 12left at4 $time $+ 12.
}

on *:text:back:#:{
  set %btime [ $+ [ $nick ] ] $time
  var %a %time [ $+ [ $chan ] ]
  msg $chan 14[[7-Away-14]]4 %nick [ $+ [ $chan ] ] 12Is now back from4 %away [ $+ [ $chan ] ] $+ 12. 4 $+ %nick 12has been away for4 $duration($calc($ctime - %a)) $+ 12.
}