my @names = glob "*" or die "Nothing to scan";
my $oldest_name = shift @names;
my $oldest_age = -M $oldest_name;
for (@names) { # remaining names
  if (-M > $oldest_age) {
    $oldest_name = $_;
    $oldest_age = -M _;
  }
}
printf "%s is %.2d days old\n", $oldest_name, $oldest_age;