my $r = undef;

my %codes = (
  hour   => sub{ $r = $notifytable_hour },
  hfhour => sub{ $r = $notifytable_hour << 1 + ( $notifytable_min > 29 ? 1 : 0 ) },
  qhour  => sub{ $r = $notifytable_hour << 2 + floor( $notifytable_min/15 ) },
  minute => sub{ $r = $notifytable_min },
  0      => sub{ $r = $notifytable_min },
);

$codes->{$rdg}->() if($codes->{$rdg}) ;