diff --git a/core/modules/views/src/Plugin/views/filter/Date.php b/core/modules/views/src/Plugin/views/filter/Date.php
index 3f77465..420dc19 100644
--- a/core/modules/views/src/Plugin/views/filter/Date.php
+++ b/core/modules/views/src/Plugin/views/filter/Date.php
@@ -3,6 +3,7 @@
 namespace Drupal\views\Plugin\views\filter;
 
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\views\Plugin\views\argument\NullArgument;
 
 /**
  * Filter to handle dates stored as a timestamp.
@@ -131,8 +132,11 @@ public function acceptExposedInput($input) {
     }
 
     // Store this because it will get overwritten.
+    $type = NULL;
     if ($this->isAGroup()) {
-      $type = $this->group_info['type'];
+      if (is_array($this->group_info)) {
+        $type = $this->group_info['type'];
+      }
     }
     else {
       $type = $this->value['type'];
@@ -159,8 +163,11 @@ public function acceptExposedInput($input) {
       }
     }
 
-    // restore what got overwritten by the parent.
-    $this->value['type'] = $type;
+    // Restore what got overwritten by the parent.
+    if (!is_null($type)) {
+      $this->value['type'] = $type;
+    }
+
     return $rc;
   }