A quick search of the Date::Manip perldoc yields this:

use Date::Manip qw(ParseDate Date_Cmp);

sub sortDate {
    my($date1, $date2);
    $date1 = &ParseDate($a);
    $date2 = &ParseDate($b);
    return (&Date_Cmp($date1,$date2));
}

my @dates = ("Fri 16 Aug 96",
             "Mon 19 Aug 96",
             "Thu 15 Aug 96");

my @i = sort &sortDate @dates;
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(edited somewhat for clarity)

You could also write this as:

my @i = sort { 
            &Date_Cmp(&ParseDate($a),&ParseDate($b)) 
        } @dates;
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