diff --git a/src/Calendar/TimesheetEntry.php b/src/Calendar/TimesheetEntry.php
index 2220f4b8..7dac69eb 100644
--- a/src/Calendar/TimesheetEntry.php
+++ b/src/Calendar/TimesheetEntry.php
@@ -32,11 +32,16 @@ final class TimesheetEntry implements DragAndDropEntry
 
     public function getData(): array
     {
+        $tags = null;
+        if (!empty($this->timesheet->getTagsAsArray())) {
+            $tags = implode(',', $this->timesheet->getTagsAsArray());
+        }
+
         return [
             'description' => $this->timesheet->getDescription(),
             'activity' => $this->timesheet->getActivity() !== null ? $this->timesheet->getActivity()->getId() : null,
             'project' => $this->timesheet->getProject() !== null ? $this->timesheet->getProject()->getId() : null,
-            'tags' => implode(',', $this->timesheet->getTagsAsArray()),
+            'tags' => $tags,
         ];
     }
 
diff --git a/src/Form/API/TimesheetApiEditForm.php b/src/Form/API/TimesheetApiEditForm.php
index 8abe4661..ef411c10 100644
--- a/src/Form/API/TimesheetApiEditForm.php
+++ b/src/Form/API/TimesheetApiEditForm.php
@@ -28,19 +28,14 @@ class TimesheetApiEditForm extends TimesheetEditForm
         if ($builder->has('user')) {
             $builder->get('user')->setRequired(false);
         }
-    }
 
-    /**
-     * Method added to prevent API BC breaks.
-     *
-     * @param FormBuilderInterface $builder
-     */
-    protected function addTags(FormBuilderInterface $builder)
-    {
-        $builder
-            ->add('tags', TagsInputType::class, [
+        if ($builder->has('tags')) {
+            $builder->remove('tags');
+            // @deprecated for BC reasons here, arrays will be supported in 2.0
+            $builder->add('tags', TagsInputType::class, [
                 'required' => false,
             ]);
+        }
     }
 
     public function configureOptions(OptionsResolver $resolver)
diff --git a/templates/reporting/report_by_user.html.twig b/templates/reporting/report_by_user.html.twig
index c04460f6..f631c489 100644
--- a/templates/reporting/report_by_user.html.twig
+++ b/templates/reporting/report_by_user.html.twig
@@ -39,7 +39,7 @@
                     {% for day in days %}
                     <th class="text-center text-nowrap{% if day.day is weekend %} weekend{% endif %}">
                         {{ day.day|day_name(true) }}<br>
-                        {{ day.day|date_format('d.m') }}
+                        {{ day.day|format_date('short') }}
                     </th>
                     {% endfor %}
                 </tr>
diff --git a/templates/reporting/report_user_list.html.twig b/templates/reporting/report_user_list.html.twig
index e42cbf7f..5f28440e 100644
--- a/templates/reporting/report_user_list.html.twig
+++ b/templates/reporting/report_user_list.html.twig
@@ -24,7 +24,7 @@
                     {% for day in days %}
                     <th class="text-center text-nowrap{% if day is weekend %} weekend{% endif %}">
                         {{ day|day_name(true) }}<br>
-                        {{ day|date_format('d.m') }}
+                        {{ day|format_date('short') }}
                     </th>
                     {% endfor %}
                 </tr>
diff --git a/templates/timesheet/layout-edit.html.twig b/templates/timesheet/layout-edit.html.twig
index 31b04d92..90f7ca43 100644
--- a/templates/timesheet/layout-edit.html.twig
+++ b/templates/timesheet/layout-edit.html.twig
@@ -248,6 +248,7 @@
                     {
                         if (durationMoment === null) {
                             getDurationField().value = '';
+                            return;
                         }
 
                         if (!durationMoment.isValid()) {