diff --git a/core/modules/datetime/datetime.module b/core/modules/datetime/datetime.module
index 67e7299..5aa8457 100644
--- a/core/modules/datetime/datetime.module
+++ b/core/modules/datetime/datetime.module
@@ -6,6 +6,7 @@
  */
 
 use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\datetime\Plugin\Field\FieldType\DateTimeItem;
 
 /**
  * Defines the timezone that dates should be stored in.
@@ -52,9 +53,10 @@ function datetime_help($route_name, RouteMatchInterface $route_match) {
  * @param $date
  *
  * @deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0. Use
- *   \Drupal\Core\Datetime\DrupalDateTime::setDefaultDateTime() instead.
+ *   \Drupal\datetime\Plugin\Field\FieldType\DateTimeItem::setDefaultDateTime()
+ *   instead.
  */
 function datetime_date_default_time($date) {
-  @trigger_error('datetime_date_default_time() is deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0. Use \Drupal\Core\Datetime\DrupalDateTime::setDefaultDateTime() instead.', E_USER_DEPRECATED);
-  $date->setTime(12, 0, 0);
+  @trigger_error('datetime_date_default_time() is deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0. Use \Drupal\datetime\Plugin\Field\FieldType\DateTimeItem::setDefaultDateTime() instead.', E_USER_DEPRECATED);
+  DateTimeItem::setDefaultDateTime($date);
 }
diff --git a/core/modules/datetime/src/DateTimeComputed.php b/core/modules/datetime/src/DateTimeComputed.php
index 9320baf..1b1e7b2 100644
--- a/core/modules/datetime/src/DateTimeComputed.php
+++ b/core/modules/datetime/src/DateTimeComputed.php
@@ -61,7 +61,7 @@ public function getValue($langcode = NULL) {
         // @todo Update comment and/or code per the chosen solution in
         //   https://www.drupal.org/node/2830094
         if ($datetime_type === DateTimeItem::DATETIME_TYPE_DATE) {
-          $this->date->setTime(12, 0, 0);
+          DateTimeItem::setDefaultDateTime($this->date);
         }
       }
     }
diff --git a/core/modules/datetime/src/Plugin/Field/FieldWidget/DateTimeWidgetBase.php b/core/modules/datetime/src/Plugin/Field/FieldWidget/DateTimeWidgetBase.php
index 7514ae8..ffec307 100644
--- a/core/modules/datetime/src/Plugin/Field/FieldWidget/DateTimeWidgetBase.php
+++ b/core/modules/datetime/src/Plugin/Field/FieldWidget/DateTimeWidgetBase.php
@@ -87,7 +87,7 @@ protected function createDefaultValue($date, $timezone) {
     // The date was created and verified during field_load(), so it is safe to
     // use without further inspection.
     if ($this->getFieldSetting('datetime_type') === DateTimeItem::DATETIME_TYPE_DATE) {
-      $date->setTime(12, 0, 0);
+      DateTimeItem::setDefaultDateTime($date);
     }
     $date->setTimezone(new \DateTimeZone($timezone));
     return $date;