#!/usr/bin/perl
use strict;
use warnings;
use Time::Local qw/ timegm_nocheck /;
use POSIX qw/ strftime /;

my $n = 4;
my ($d, $m, $y) = (gmtime)[3..5];
my $gmtime = strftime "%d/%b/%Y", gmtime timegm_nocheck 0,0,0, $d-$n, $m, $y;
$gmtime =~ s/^(?:0| )//;

while(<DATA>){
	print if /$gmtime\b/;
}