#!/usr/local/bin/perl -w
use strict;
use warnings;
use Date::Parse;

# date strings in various format
my @date = ( 'Apr 8 1984',
             'Apr 08 84',
             '4/8/84',
             '04/08/84',
             '08 Apr 1984' );

my @months = qw/ January February March April May June July
                 August September October November December /;

foreach (@date) {
    my ($day,$month,$year) = (strptime $_)[3,4,5];
    printf "%s %d %d\n", $months[$month], $day, $year + 1900;
}
[download]

And the output -

April 8 1984
April 8 1984
April 8 1984
April 8 1984
April 8 1984
[download]