make sure that timezone is properly validated (#2663)

src/Validator/Constraints/TimesheetBudgetUsed.php

@@ -0,0 +1,17 @@
+<?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\Validator\Constraints;
+
+final class TimesheetBudgetUsed extends TimesheetConstraint
+{
+    // same messages, so we can re-use the validation translation!
+    public $messageRate = 'The budget is completely used.';
+    public $messageTime = 'The budget is completely used.';
+}