Php full browsing history

<?php

echo date("l, F d, Y h:i" ,time());
$filename="3.php";
$last_modified = filemtime($filename);
echo"<br><br>";
print "Last modified " .$filename." ". date("l, dS F, Y @ h:ia", $last_modified);
echo"<br><br><br><br>";
echo "<p>IP Address: " . $_SERVER['REMOTE_ADDR'] . "</p>";
//echo "<p>Referrer: " . $_SERVER['HTTP_REFERER'] . "</p>";
echo "<p>Browser: " . $_SERVER['HTTP_USER_AGENT'] . "</p>";
echo"<br><br><br><br>";
$time = microtime();
$time = explode(" ", $time);
$time = $time[1] + $time[0];
$start = $time;

$time = microtime();
$time = explode(" ", $time);
$time = $time[1] + $time[0];
$finish = $time;
$totaltime = ($finish - $start);
printf ("This page took %f seconds to load.", $totaltime);
?>