You can easily do it yourself:

use strict;
use warnings;

my $str = shift @ARGV;
my %months = (
          'Jan' => '01',
          'Feb' => '02',
          'Mar' => '03',
          'Apr' => '04',
          'May' => '05',
          'Jun' => '06',
          'Jul' => '07',
          'Aug' => '08',
          'Sep' => '09',
          'Oct' => '10',
          'Nov' => '11',
          'Dec' => '12'
         );

my ($year,$month,$day) = (substr ($str,-2,2,""),substr($str,-3,3,""),$
+str);
my $modstr = join '-',($months{$month},length $day == 1 ? '0'.$day : $
+day, '20'.$year);

print $modstr."\n";

# Run it!:
# perl date_convert.pl 16May07
# 05-16-2007
# perl date_convert.pl 4Dec03
# 12-04-2003
[download]

But be careful with years < 2000! :-)

citromatik