diff --git a/core/modules/datetime/lib/Drupal/datetime/Plugin/field/widget/DatetimeDatelistWidget.php b/core/modules/datetime/lib/Drupal/datetime/Plugin/field/widget/DatetimeDatelistWidget.php
index f0d60fe..78ed2dd 100644
--- a/core/modules/datetime/lib/Drupal/datetime/Plugin/field/widget/DatetimeDatelistWidget.php
+++ b/core/modules/datetime/lib/Drupal/datetime/Plugin/field/widget/DatetimeDatelistWidget.php
@@ -36,25 +36,6 @@
 class DateTimeDatelistWidget extends WidgetBase {
 
   /**
-   * {@inheritdoc}
-   */
-  public function __construct($plugin_id, array $plugin_definition, FieldInstance $instance, array $settings) {
-    // Identify the function used to set the default value.
-    $instance['default_value_function'] = $this->defaultValueFunction();
-    parent::__construct($plugin_id, $plugin_definition, $instance, $settings);
-  }
-
-  /**
-   * Returns the callback used to set a date default value.
-   *
-   * @return string
-   *   The name of the callback to use when setting a default date value.
-   */
-  public function defaultValueFunction() {
-    return 'datetime_default_value';
-  }
-
-  /**
    * Implements \Drupal\field\Plugin\Type\Widget\WidgetInterface::formElement().
    */
   public function formElement(array $items, $delta, array $element, $langcode, array &$form, array &$form_state) {
diff --git a/core/modules/datetime/lib/Drupal/datetime/Plugin/field/widget/DatetimeDefaultWidget.php b/core/modules/datetime/lib/Drupal/datetime/Plugin/field/widget/DatetimeDefaultWidget.php
index f0c45c0..ffffb66 100644
--- a/core/modules/datetime/lib/Drupal/datetime/Plugin/field/widget/DatetimeDefaultWidget.php
+++ b/core/modules/datetime/lib/Drupal/datetime/Plugin/field/widget/DatetimeDefaultWidget.php
@@ -30,25 +30,6 @@
 class DateTimeDefaultWidget extends WidgetBase {
 
   /**
-   * {@inheritdoc}
-   */
-  public function __construct($plugin_id, array $plugin_definition, FieldInstance $instance, array $settings) {
-    // Identify the function used to set the default value.
-    $instance['default_value_function'] = $this->defaultValueFunction();
-    parent::__construct($plugin_id, $plugin_definition, $instance, $settings);
-  }
-
-  /**
-   * Return the callback used to set a date default value.
-   *
-   * @return string
-   *   The name of the callback to use when setting a default date value.
-   */
-  public function defaultValueFunction() {
-    return 'datetime_default_value';
-  }
-
-  /**
    * Implements \Drupal\field\Plugin\Type\Widget\WidgetInterface::formElement().
    *
    */