#! perl
use Modern::Perl;

my $a = "December 14th 2012";
my $b = "December 21st 2012";
my $c = "December 22nd 2012";

for ($a, $b, $c)
{
    my @fields = split;
    $fields[1] =~ s/st|nd|rd|th//;
    $_ = join(' ', @fields);
    say;
}