<?php function Diferenca($hora1, $hora2=""){  if($hora2==""){ $hora2 = date("H:i:s"); }  for($i=1;$i<=2;$i++){ ${"horas".$i} = substr(${"hora".$i},0,2); ${"minutos".$i} = substr(${"hora".$i},3,2); ${"segundos".$i} = substr(${"hora".$i},6,2); }  $dia = date(d); $mes = date(m); $ano = date(Y);  $segundos = mktime($horas2,$minutos2,$segundos2,$mes,$dia,$ano)-mktime($horas1,$minutos1,$segundos1,$mes,$dia,$ano);  return date("H:i:s",mktime(0,0,$segundos,$mes,$dia,$ano));  }    echo "<a href='index.php'>voltar</a><br />"; //echo "<a href='exportar.php'>exportar</a><br />"; //echo "<a href='exportar2.php'>exportar2</a><br />"; echo "<a href='exportar3.php'>exportar</a><br />";   //$id = $_SESSION['username']  $con = mysql_connect("localhost","root",""); if (!$con) { die('Could not connect: ' . mysql_error()); }  mysql_select_db("my", $con);  $result = mysql_query("SELECT * FROM Persons"); //DATEDIFF(entra, sai) as diferenca FROM //SELECT campos, DATEDIFF(entra, sai) as diferenca FROM... //$result2 = mysql_query("SELECT DATEDIFF(entra, sai) FROM persons");   $data1 = $row['entra']; $data2 = $row['sai']; //$datadif = echo datediff('$sai', '$entra'); //chamamos a função e imprimimos //echo calcular_tempo_trasnc($entra, $sai);   echo "<table border=0' style='background-color:#F2B600'> <tr> <th>nome</th> <th>dia</th> <th>mes</th> <th>ano</th> <th>turno</th> <th>entra</th> <th>sai</th> </tr>";  while($row = mysql_fetch_array($result)) { echo "<tr style='background-color:#FFFF66'>"; echo "<td>" . $row['nome] . "</td>"; echo "<td>" . $row['dia'] . "</td>"; echo "<td>" . $row['mes'] . "</td>"; echo "<td>" . $row['ano'] . "</td>"; echo "<td>" . $row['turno'] . "</td>"; echo "<td>" . $row['entra'] . "</td>"; echo "<td>" . $row['sai'] . "</td>"; echo "<td>" . Diferenca($data1,$data2) . "</td>";  echo "</tr>"; } echo "</table>";  mysql_close($con);  ?>