Is no one paying attention to the fact that the OP is using `ls -lto ...` to get the modification time of the files? I strongly suggest you use stat() or the -M filetest for this instead. It's much cleaner, faster, and system-independent, and there's no hairy regex necessary for parsing out the date. And by the way, my `ls -lto ...` doesn't zero-pad the day, so your regex would fail on my system.

my @months = qw( Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec );
my @dates;
for my $f (@files) {
  my $mod_time = (stat $f)[9];
  my ($min, $hour, $day, $mon) = (localtime $mod_time)[1..4];
  print "$f modified on $months[$mon] $day, $hour:$min\n";
  # or if you want zero-padding...
  printf "%s modified on %3s %02d, %02d:%02d\n", $f, $months[$mon], $d
+ay, $hour, $min;
}
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Please see stat for more details.