Mine

on *:text:brb*:#: { msg $chan $c1($nick) 14[10is now AFK14] [10Reason14] $c2($iif(!$2,None Specified,$2-)) 14[3BBS14]
  %awaytest = $ctime
  %reas0n = $iif(!$2,None Specified,$2-)
}
on *:text:back:#: { msg $chan 14[10Yay14] $c1($nick) 14[10is back from14] $c2(%reas0n) 14[10he was away for14] $c2($duration($calc($ctime - %awaytest))) 14[3:D WELCOME BACK14]2 $nick
  unset %reas0n
  unset %awaytest
} 
alias c1 { return 02 $+ $1- } 
alias c2 { return 04 $+ $1- }