Parse dates using the correct format from the language pack on view access page

htdocs/view/access.php

@@ -244,17 +244,17 @@ function editaccess_validate(Pieform $form, $values) {
     $loggedinaccess = false;
     if ($values['accesslist']) {
         foreach ($values['accesslist'] as &$item) {
-            if (!isset($item['startdate'])) {
+            if (empty($item['startdate'])) {
                 $item['startdate'] = null;
             }
-            else if (!$item['startdate'] = strtotime($item['startdate'])) {
+            else if (!$item['startdate'] = strptime($item['startdate'], get_string('strftimedatetimeshort'))) {
                 $form->set_error('accesslist', get_string('unrecogniseddateformat', 'view'));
                 break;
             }
-            if (!isset($item['stopdate'])) {
+            if (empty($item['stopdate'])) {
                 $item['stopdate'] = null;
             }
-            else if (!$item['stopdate'] = strtotime($item['stopdate'])) {
+            else if (!$item['stopdate'] = strptime($item['stopdate'], get_string('strftimedatetimeshort'))) {
                 $form->set_error('accesslist', get_string('invaliddate', 'view'));
                 break;
             }