diff --git a/core/modules/datetime/datetime.module b/core/modules/datetime/datetime.module
index 1078541..103a8bb 100644
--- a/core/modules/datetime/datetime.module
+++ b/core/modules/datetime/datetime.module
@@ -50,6 +50,9 @@ function datetime_help($route_name, RouteMatchInterface $route_match) {
  * same value for in both the local timezone and UTC.
  *
  * @param $date
+ *
+ * @deprecated in Drupal 8.3.0 and will be removed before Drupal 9.0.0. Use
+ *   (TBD) instead.
  */
 function datetime_date_default_time($date) {
   $date->setTime(12, 0, 0);
diff --git a/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeCustomFormatter.php b/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeCustomFormatter.php
index 678ddc8..a2ef7d5 100644
--- a/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeCustomFormatter.php
+++ b/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeCustomFormatter.php
@@ -40,10 +40,6 @@ public function viewElements(FieldItemListInterface $items, $langcode) {
         /** @var \Drupal\Core\Datetime\DrupalDateTime $date */
         $date = $item->date;
 
-        if ($this->getFieldSetting('datetime_type') == 'date') {
-          // A date without time will pick up the current time, use the default.
-          datetime_date_default_time($date);
-        }
         $this->setTimeZone($date);
 
         $output = $this->formatDate($date);
diff --git a/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeDefaultFormatter.php b/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeDefaultFormatter.php
index 03c92ae..e0fe538 100644
--- a/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeDefaultFormatter.php
+++ b/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeDefaultFormatter.php
@@ -42,11 +42,6 @@ public function viewElements(FieldItemListInterface $items, $langcode) {
         /** @var \Drupal\Core\Datetime\DrupalDateTime $date */
         $date = $item->date;
 
-        if ($this->getFieldSetting('datetime_type') == 'date') {
-          // A date without time will pick up the current time, use the default.
-          datetime_date_default_time($date);
-        }
-
         // Create the ISO date in Universal Time.
         $iso_date = $date->format("Y-m-d\TH:i:s") . 'Z';
 
diff --git a/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimePlainFormatter.php b/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimePlainFormatter.php
index 683d75c..a8ff469 100644
--- a/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimePlainFormatter.php
+++ b/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimePlainFormatter.php
@@ -30,10 +30,6 @@ public function viewElements(FieldItemListInterface $items, $langcode) {
         /** @var \Drupal\Core\Datetime\DrupalDateTime $date */
         $date = $item->date;
 
-        if ($this->getFieldSetting('datetime_type') == 'date') {
-          // A date without time will pick up the current time, use the default.
-          datetime_date_default_time($date);
-        }
         $this->setTimeZone($date);
 
         $output = $this->formatDate($date);
diff --git a/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeTimeAgoFormatter.php b/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeTimeAgoFormatter.php
index 859ea5d..e79a94a 100644
--- a/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeTimeAgoFormatter.php
+++ b/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeTimeAgoFormatter.php
@@ -110,10 +110,6 @@ public function viewElements(FieldItemListInterface $items, $langcode) {
       $date = $item->date;
       $output = [];
       if (!empty($item->date)) {
-        if ($this->getFieldSetting('datetime_type') == 'date') {
-          // A date without time will pick up the current time, use the default.
-          datetime_date_default_time($date);
-        }
         $output = $this->formatDate($date);
       }
       $elements[$delta] = $output;
diff --git a/core/modules/datetime/src/Plugin/Field/FieldWidget/DateTimeWidgetBase.php b/core/modules/datetime/src/Plugin/Field/FieldWidget/DateTimeWidgetBase.php
index aa6175a..c36f87f 100644
--- a/core/modules/datetime/src/Plugin/Field/FieldWidget/DateTimeWidgetBase.php
+++ b/core/modules/datetime/src/Plugin/Field/FieldWidget/DateTimeWidgetBase.php
@@ -44,11 +44,6 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
       $date = $items[$delta]->date;
       // The date was created and verified during field_load(), so it is safe to
       // use without further inspection.
-      if ($this->getFieldSetting('datetime_type') == DateTimeItem::DATETIME_TYPE_DATE) {
-        // A date without time will pick up the current time, use the default
-        // time.
-        datetime_date_default_time($date);
-      }
       $date->setTimezone(new \DateTimeZone($element['value']['#date_timezone']));
       $element['value']['#default_value'] = $date;
     }
@@ -68,9 +63,6 @@ public function massageFormValues(array $values, array $form, FormStateInterface
         $date = $item['value'];
         switch ($this->getFieldSetting('datetime_type')) {
           case DateTimeItem::DATETIME_TYPE_DATE:
-            // If this is a date-only field, set it to the default time so the
-            // timezone conversion can be reversed.
-            datetime_date_default_time($date);
             $format = DATETIME_DATE_STORAGE_FORMAT;
             break;
 
diff --git a/core/modules/datetime_range/src/DateTimeRangeTrait.php b/core/modules/datetime_range/src/DateTimeRangeTrait.php
index 5a34f2c..69df5cc 100644
--- a/core/modules/datetime_range/src/DateTimeRangeTrait.php
+++ b/core/modules/datetime_range/src/DateTimeRangeTrait.php
@@ -20,10 +20,6 @@
    *   A render array.
    */
   protected function buildDate(DrupalDateTime $date) {
-    if ($this->getFieldSetting('datetime_type') == DateTimeItem::DATETIME_TYPE_DATE) {
-      // A date without time will pick up the current time, use the default.
-      datetime_date_default_time($date);
-    }
     $this->setTimeZone($date);
 
     $build = [
@@ -48,11 +44,6 @@ protected function buildDate(DrupalDateTime $date) {
    *   A render array.
    */
   protected function buildDateWithIsoAttribute(DrupalDateTime $date) {
-    if ($this->getFieldSetting('datetime_type') == DateTimeItem::DATETIME_TYPE_DATE) {
-      // A date without time will pick up the current time, use the default.
-      datetime_date_default_time($date);
-    }
-
     // Create the ISO date in Universal Time.
     $iso_date = $date->format("Y-m-d\TH:i:s") . 'Z';
 
diff --git a/core/modules/datetime_range/src/Plugin/Field/FieldWidget/DateRangeWidgetBase.php b/core/modules/datetime_range/src/Plugin/Field/FieldWidget/DateRangeWidgetBase.php
index 87cecbb..30f58af 100644
--- a/core/modules/datetime_range/src/Plugin/Field/FieldWidget/DateRangeWidgetBase.php
+++ b/core/modules/datetime_range/src/Plugin/Field/FieldWidget/DateRangeWidgetBase.php
@@ -54,9 +54,6 @@ public function massageFormValues(array $values, array $form, FormStateInterface
         $start_date = $item['value'];
         switch ($this->getFieldSetting('datetime_type')) {
           case DateRangeItem::DATETIME_TYPE_DATE:
-            // If this is a date-only field, set it to the default time so the
-            // timezone conversion can be reversed.
-            datetime_date_default_time($start_date);
             $format = DATETIME_DATE_STORAGE_FORMAT;
             break;
 
@@ -84,9 +81,6 @@ public function massageFormValues(array $values, array $form, FormStateInterface
         $end_date = $item['end_value'];
         switch ($this->getFieldSetting('datetime_type')) {
           case DateRangeItem::DATETIME_TYPE_DATE:
-            // If this is a date-only field, set it to the default time so the
-            // timezone conversion can be reversed.
-            datetime_date_default_time($end_date);
             $format = DATETIME_DATE_STORAGE_FORMAT;
             break;
 
@@ -155,11 +149,6 @@ public function validateStartEnd(array &$element, FormStateInterface $form_state
   protected function createDefaultValue($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) {
-      // A date without time will pick up the current time, use the default
-      // time.
-      datetime_date_default_time($date);
-    }
     $date->setTimezone(new \DateTimeZone($timezone));
     return $date;
   }