#!/usr/bin/env perl -l

use strict;
use warnings;

use Time::Piece;

my %myHash;
my $format = '%m/%d/%Y %H:%M:%S';

while (<DATA>) {
    my ($date, $time, $data1, $data2) = split;
    my $sort_key = Time::Piece->strptime("$date $time", $format)->epoch;
    push @{$myHash{$data2}{info}}, "$sort_key:$date,$time,$data1";
}

for my $key (sort keys %myHash) {
    print "$_,$key" for
        map { $_->[1] }
        sort { $a->[0] <=> $b->[0] }
        map { [ split /:/, $myHash{$key}{info}[$_], 2 ] }
        0 .. $#{$myHash{$key}{info}};
}

__DATA__
01/14/2014 23:44:14 A Y
01/14/2014 23:44:12 B Y
01/14/2014 23:44:13 C X
01/14/2014 23:44:12 D X