http://phpsnips.com/459/visit-counter#.VBG_8_mSySp

visit_counter.php

<?php 
// set the variable to 0, it'll matter only if the cookie for the variable is not set 
$visitCounter = 0; 
// if cookie is set for the variable, it'll go to $visitCounter and get added by 1; otherwise it'll show 0 for tha variable 
if(isset($_COOKIE['visitCounter'])){ 
    $visitCounter = $_COOKIE['visitCounter']; 
    $visitCounter ++; 
} 
// if the last visist cookie is set, it'll pass the value to $lastVisit, and it'll be displayed below; 
if(isset($_COOKIE['lastVisit'])){ 
    $lastVisit = $_COOKIE['lastVisit']; 
     
} 
// set cookie for visitCounter 
setcookie('visitCounter', $visitCounter+1,  time()+3600);  
// set cookie for last visit 
setcookie('lastVisit', date("d-m-Y H:i:s"),  time()+3600);  
// show the respected values 

// is the variable is not set, say 'welcome', otherwise show the info about visit number and last visit date 
if($visitCounter == 0){ 
    echo "Welcome"; 
} else { 

echo "This is your visit number ".$visitCounter; 
echo '<br>'; 
echo "Last time, you were here ".$lastVisit; 

} 



?>