controlador-descarga/views/reporte/index.php

<?php

/* @var $descargas app\models\Descarga[] */
/* @var $estaciones array */
/* @var $primer \DateTime */
/* @var $ultimo \DateTime */

?>
<style>
  .site-card {
    min-height: 100vh;
    width: 100vw;
    padding: 20px;
    background: #ececec;
  }

  .content {
    width: 100%;
    height: 100%;
  }

  .full-width {
    width: 100%;
  }
</style>
<div>
  <table border="1" width="100%" id="tabla">
    <tr>
      <th>pc</th>
      <th>ciudad</th>
      <th>clave</th>
      <th>siglas</th>
      <th>frecuencia</th>
      <?php $f = (clone $primer); ?>
      <?php while($f <= $ultimo): ?>
        <th>
        <?= $f->format("d/m/Y") ?>
        </th>
        <?php $f->add(new \DateInterval("P1D")); ?>
      <?php endwhile; ?>
    </tr>
    <?php $estacion = ""; ?>
    <?php foreach ($estaciones as $pc => $est): ?>
      <?php foreach($est as $clave => $info): ?>
        <tr>
          <td><?= $pc ?></td>
          <td><?= $info['ciudad'] ?></td>
          <td><?= $clave ?></td>
          <td><?= $info['siglas'] ?></td>
          <td><?= $info['frecuencia'] ?></td>
          <?php $fecha = (clone $primer); ?>
          <?php while($fecha <= $ultimo): ?>
            <?php $d = null; ?>
            <?php if(isset($descargas[$pc][$clave][$fecha->format("Y-m-d")])): ?>
              <?php $d = $descargas[$pc][$clave][$fecha->format("Y-m-d")]; ?>
            <?php endif; ?>
            <?php if($d !== null): ?>
              <td style="background-color: <?= $d["color"] ?>; text-align: center ">
              <?= $d["descargados"] ?> / <?= $d["total"] ?>
              </td>
            <?php else: ?>
              <td></td>
            <?php endif; ?>
            <?php $fecha->add(new \DateInterval("P1D")); ?>
          <?php endwhile ?>
        </tr>
      <?php endforeach ?>
    <?php endforeach ?>
  </table>
</div>