Most likely, an easier way to do this is using sprintf:

sub makeDate {
  my ($sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst) = l
+ocaltime(time);

  $year += 1900;
  $mon++;

  sprintf "%02d_%02d_%04d_%02d%02d%02d",
          $mon, $mday, $year,
          $hour, $min, $sec;
}
[download]

Even better may be to use POSIX::strftime or one of the many Date modules.

sub makeDate {
  require POSIX;
  POSIX::strftime("%m_%d_%Y_%H%M%S", localtime(time));
}
[download]