Date::Manip can do quite a lot, but not everything. Check this test script.

#!/usr/bin/perl -w
use strict;
use Date::Manip;
while (<DATA>) {
    chomp;
    my $date = ParseDate($_);
    if ($date) {
        print "$_ \t=> ",  UnixDate($date,"%b %e, %Y."),"\n";
    }
    else {
        print "$_ \t=> not a valid date\n";
    }
}

__DATA__
19971103
11031997
11.03.1997
19983201
20031110
20031011
1993jan02
2002dec08
yesterday
today
tomorrow
Aug12
12Aug2003
Aug122003
122003Aug
[download]

output:

19971103        => Nov  3, 1997.
11031997        => not a valid date
11.03.1997      => Nov  3, 1997.
19983201        => not a valid date
20031110        => Nov 10, 2003.
20031011        => Oct 11, 2003.
1993jan02       => Jan  2, 1993.
2002dec08       => Dec  8, 2002.
yesterday       => Sep 29, 2003.
today           => Sep 30, 2003.
tomorrow        => Oct  1, 2003.
Aug12           => Aug 12, 2003.
12Aug2003       => Aug 12, 2003.
Aug122003       => Aug 12, 2003.
122003Aug       => Aug 12, 2003.
[download]

Your 11031997 is not recognized as it is, but it is parsed correctly if you add dots. Check the documentation to see which formats are recognized. You see from the example that it is quite flexible.

Be aware, though, that Date::Manip is very slow compared to direct regexp manipulation. Check the docs for this issue as well.

HTH