How to make an alert message related to the date date?

My idea is to show an alert icon in the date record that is about to expire, I understand I have a system where requests are entered, if the request is not answered within a period of 10 days it will be automatically displayed the alert icon

   <?php
    require "PDO_Pagination.php";

     /* Config Connection */
        $root = 'root';
   $password = '';
   $host = 'localhost';
   $dbname = 'bdpagina';

   $connection = new PDO("mysql:host=$host;dbname=$dbname;", $root, $password);
   $pagination = new PDO_Pagination($connection);

   $search = null;
  if(isset($_REQUEST["search"]) && $_REQUEST["search"] != "")
  {
  $search = htmlspecialchars($_REQUEST["search"]);
  $pagination->param = "&search=$search";
  $pagination->rowCount("SELECT * FROM contribuyente WHERE nombre LIKE '%$search%' OR id LIKE '%$search%' OR estado LIKE '%$search%'");
  $pagination->config(3, 10);
   $sql = "SELECT * FROM contribuyente WHERE nombre LIKE '%$search%' OR id LIKE '%$search%' OR estado LIKE '%$search%' ORDER BY id ASC LIMIT $pagination->start_row, $pagination->max_rows";
  $query = $connection->prepare($sql);
  $query->execute();
  $model = array();
   while($rows = $query->fetch())
    {
    $model[] = $rows;
     }
     }
    else
    {
    $pagination->rowCount("SELECT * FROM contribuyente WHERE estado in ('Pendiente','Resuelto')  ORDER BY id'");
    $pagination->config(3, 10);
    $sql = "SELECT * FROM contribuyente WHERE estado in ('Pendiente','Resuelto')   ORDER BY id  ASC LIMIT $pagination->start_row, 
    $pagination->max_rows";
    $query = $connection->prepare($sql);
    $query->execute();
    $model = array();
     while($rows = $query->fetch())
       {
      $model[] = $rows;
         }
         }
      ?>

   <form method="POST" action="<?php echo $_SERVER["PHP_SELF"] ?>">
Buscar: 
   <input type="text" name="search" placeholder="Buscar folio/estado" value="<?php echo $search ?>">
   <input type="submit" value="Buscar">
   </form>
 <br><br>
  <center>
    <table class="table table-striped table-hover">
  <tr>
   <th>Folio</th>
      <th>Nombre</th>
      <th>Rut</th>
      <th>Correo</th>
      <th>Telefono</th>
      <th>Direccion</th>
      <th>Poste</th>
      <th>Solicitud</th>
      <th>Fecha</th>
      <th>Estado</th>
      <th>Reporte</th>
      <th>Borrar</th>

    </tr>
    <?php
   foreach($model as $row)
   {
    echo "<tr>";
    echo "<td>".$row['id']."</td>";
    echo "<td>".$row['nombre']."</td>";

    echo "<td>".$row['rut']."</td>";
    echo "<td>".$row['email']."</td>";
    echo "<td>".$row['phone']."</td>";
    echo "<td>".$row['direccion']."</td>";
    echo "<td>".$row['poste']."</td>";
    echo "<td>".$row['mensaje']."</td>";
    echo "<td>".$row['fecha']."</td>";

   echo "<td>";
      if($row['estado'] == 'Resuelto'){
        echo '<span class="label label-success">Resuelto</span>';
      }
                    elseif ($row['estado'] == 'Pendiente' ){
        echo '<span class="label label-warning">Pendiente</span>';
      }
                    elseif ($row['estado'] == 'Rechazado' ){
        echo '<span class="label label-danger">Rechazado</span>';
      }
       elseif ($row['estado'] == 'Resuelta' ){
        echo '<span class="label label-success">Resuelta</span>';
      }

    echo "</td>";
    echo "<td><a href='actualizar.php?id=$row[0]' title='Editar datos' class='btn btn-primary btn-sm'><span class='glyphicon glyphicon-edit' aria-hidden='true'></span></td>";
      echo "<td><a href='eliminar.php?id=$row[0]&idborrar=2'' title='Eliminar'  class='btn btn-danger btn-sm'><span class='glyphicon glyphicon-trash' aria-hidden='true'></span></a><th>";
    echo "</tr>";
}
  ?>
  </table>
    <br>
    <br>

  <div>
  <?php
  $pagination->pages("btn");
   ?>
   </div>
    </center>
     <br>
     <br>
     <br>
     <br>
    </body>
 </html>