Created new render helper for the timezone dropdown.

application/config/autoload.php

@@ -65,7 +65,7 @@ $autoload['libraries'] = ['database'];
 |	$autoload['helper'] = array('url', 'file');
 */
 
-$autoload['helper'] = ['custom_exceptions', 'url', 'file', 'language', 'asset', 'config'];
+$autoload['helper'] = ['custom_exceptions', 'url', 'file', 'language', 'asset', 'config', 'render'];
 
 
 /*

application/helpers/render_helper.php

@@ -0,0 +1,33 @@
+<?php defined('BASEPATH') OR exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Open Source Web Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) 2013 - 2020, Alex Tselegidis
+ * @license     http://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        http://easyappointments.org
+ * @since       v1.4.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Render the HTML output of a timezone dropdown element.
+ *
+ * @param string $attributes HTML element attributes of the dropdown.
+ * @return false|string
+ */
+function render_timezone_dropdown($attributes = '')
+{
+    $framework = get_instance();
+
+    $framework->load->model('timezones_model');
+
+    $timezones = $framework->timezones_model->to_grouped_array();
+
+    ob_start();
+
+    require __DIR__ . '/../views/partial/timezone_dropdown.php';
+
+    return ob_get_clean();
+}

application/views/partial/timezone_dropdown.php

@@ -0,0 +1,10 @@
+<select <?= $attributes ?>>
+    <option value="UTC">UTC</option>
+    <?php foreach ($timezones as $continent => $entries): ?>
+        <optgroup label="<?= $continent ?>">
+            <?php foreach ($entries as $value => $name): ?>
+                <option value="<?= $value ?>"><?= $name ?></option>
+            <?php endforeach ?>
+        </optgroup>
+    <?php endforeach ?>
+</select>