configure first day of week for calendar and date-picker (#1952)

src/Form/Type/FirstWeekDayType.php

@@ -0,0 +1,46 @@
+<?php
+
+/*
+ * This file is part of the Kimai time-tracking app.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace App\Form\Type;
+
+use Symfony\Component\Form\AbstractType;
+use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
+use Symfony\Component\OptionsResolver\OptionsResolver;
+
+/**
+ * Custom form field type to select the first of the week.
+ */
+class FirstWeekDayType extends AbstractType
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function configureOptions(OptionsResolver $resolver)
+    {
+        $choices = [
+            'Monday' => 'monday',
+            'Sunday' => 'sunday'
+        ];
+
+        $resolver->setDefaults([
+            'multiple' => false,
+            'choices' => $choices,
+            'label' => 'first_weekday',
+            'translation_domain' => 'system-configuration'
+        ]);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getParent()
+    {
+        return ChoiceType::class;
+    }
+}