icingaweb2/modules/monitoring/application/views/scripts/show/components/checktimeperiod.phtml

<?php if (isset($object->service_check_timeperiod)): ?>

<tr>
    <th><?= $this->translate('Check Timeperiod') ?></th>
    <td>
        <?= $object->service_check_timeperiod ?>
    </td>
</tr>

<?php endif ?>

<?php if (isset($object->host_check_timeperiod)): ?>

    <tr>
        <th><?= $this->translate('Check Timeperiod') ?></th>
        <td>
            <?= $object->host_check_timeperiod ?>
        </td>
    </tr>

<?php endif ?>