my %BACKUP_DAY = (
   Sunday    => 0,
   Monday    => 1,
   Tuesday   => 2,
   Wednesday => 3,
   Thursday  => 4,
   Friday    => 6,
);

chomp(my $runday = `/bin/date +%A`);
my $slot = $BACKUP_DAY{$runday};
print "Slot Number is $slot\n";