Mine

alias away {
  set %time $ctime 
  set %away $+ .nick $nick 
  set %away.time $time 
  set %away.ctime $ctime 
  set %away.able on 
  set %reason $iif($1,$1-)
  amsg 3,11I am away Reason: %reason $+.  Left at: %away.time | 
  nick iDontPm|Away
}
alias back {
  set %away.able off
  amsg 3,11I am back From: %reason $+ . Gone for: $duration($calc($ctime - %away.ctime)) 
  nick iDontPm 
  unset %away.
  unset %back.
}