use warnings;
use strict;
use File::ReadBackwards;

die "Usage: $0 LOGFILE\n" unless @ARGV==1;
my $FILE = shift @ARGV;

my $bw = File::ReadBackwards->new($FILE)
	or die "Can't read $FILE: $!" ;
LINE: while(defined( my $line = $bw->readline )) {
	chomp($line);
	if ( $line =~ /received/ ) {
		my ($dt) = $line =~ /^([\d\/]+\s+[\d\:]+)\b/
			or die "Failed to parse date from: $line\n";
		print "$dt\n";
		last LINE;
	}
}
$bw->close;