Difference between timestamps

I am working on a little project that I hope to use at work on just a local server.
We operate a golf dome and charge by the amount of time people are in the dome hitting golf balls. I want people to be able to enter their name and a pin that clocks the time that they enter the dome to a database. When they enter they name and pin again the time they exit the dome. Then display the difference in hours and minutes only (people wont hit for a day +). and if possible when they clock out I want it to remove the name from the database.
My database is set up like this:
This is what I have so far.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">


<meta http-equiv="content-type" content="text/html; charset=utf-8" />

<meta name="description" content="" />

<meta name="keywords" content="" />

<meta name="author" content="" />

<link rel="stylesheet" type="text/css" href="style.css" media="screen" />

<title>Dome time clock</title>



		<div id="wrapper">

<div id="content">

		<div align="center"><h2><small>time clock</small></h2></div><br>
		<table width="100%">
 // Connects to your Database 

 mysql_connect("localhost", "root", "") or die(mysql_error()); 

 mysql_select_db("timelog") or die(mysql_error()); 

 //This code runs if the form has been submitted

 if (isset($_POST['submit'])) { 

 //This makes sure they did not leave any fields blank

 if (!$_POST['name'] | !$_POST['pin'] | !$_POST['pin2'] ) {

 		die('You did not complete all of the required fields. <a href="javascript:history.go(-1)">Go Back</a>');


 // checks if the username is in use

 	if (!get_magic_quotes_gpc()) {

 		$_POST['name'] = addslashes($_POST['name']);


 $usercheck = $_POST['name'];

 $check = mysql_query("SELECT name FROM log WHERE name = '$usercheck'") 

or die(mysql_error());

 $check2 = mysql_num_rows($check);

 //if the name exists it gives an error

 if ($check2 != 0) {

 		die('Sorry, "'.$_POST['name'].'" is already in use. <a href="javascript:history.go(-1)">Go Back</a>');


 // this makes sure both passwords entered match

 	if ($_POST['pin'] != $_POST['pin2']) {

 		die('Your PIN did not match. <a href="javascript:history.go(-1)">Go Back</a> ');


 	// here we encrypt the password and add slashes if needed

 	$_POST['pin'] = md5($_POST['pin']);

 	if (!get_magic_quotes_gpc()) {

 		$_POST['pin'] = addslashes($_POST['pin']);

 		$_POST['name'] = addslashes($_POST['name']);


 // now we insert it into the database

 	$insert = "INSERT INTO log (name, pin)

 			VALUES ('".$_POST['name']."', '".$_POST['pin']."')";

 	$add_member = mysql_query($insert);


 <h1>Thank's <?php echo $_POST['name'] ?> you are now clocked inn. Enjoy! <a href="javascript:history.go(-1)">Go Back</a></h1>



 <form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post">

 <table border="0">


 <input type="text" name="name" maxlength="60">



 <input type="password" name="pin" maxlength="10">


 <tr><td>Confirm Password:</td><td>

 <input type="password" name="pin2" maxlength="10">


 <tr><th colspan=2><input type="submit" name="submit" 
value="Clock in/out"></th></tr> </table>




</div> <!-- end #content -->



sounds like you want to use the TIMESTAMPDIFF function

That’s what I was thinking. Am I going to have to make a form for the clock out part as well? Or can I use the same form and make a different query to send the timestamp to the time_out column? When I try to enter the name and pin again I comes up with my error that the name already in use.

most likely the latter

but the proof, as they say, is in the coding

How can I get the difference in time in hours and minutes using something like this. I want the start time to be pulled from the db and the current time to be logged when submitting the form. Also if you guys dont mind showing me how to make an error when name and pin do not match the row in the db.

 if (isset($_POST['submit'])) { 

 //This makes sure they did not leave any fields blank

 if (!$_POST['name'] | !$_POST['pin']  ) {

 		die('You did not complete all of the required fields. <a href="javascript:history.go(-1)">Go Back</a>');


date_default_timezone_set ("America/Denver");
$time = date( "Y-m-d : H:i:s", time());
$name = $_POST["name"];
$pin = $_POST["pin"];

 // now checks database for match

 	$result = mysql_query("SELECT * FROM log
WHERE name LIKE '$name' and pin LIKE '$pin'");

while($row = mysql_fetch_array($result))
  echo "Timecard for: <b>" . $row['name'] . "</b>";
  echo "<br />";	
  echo "Clocked in at: " . $row['time_in'];
  echo "<br />";
  echo "Current time: $time";
  echo "<br />"
  $dateDiff    = ['time_in'] - $time;
   $fullHours   = floor(($dateDiff-($fullDays*60*60*24))/(60*60));
   $fullMinutes = floor(($dateDiff-($fullDays*60*60*24)-($fullHours*60*60))/60);
   echo " $fullHours hours and $fullMinutes minutes.";