diff --git a/core/modules/datetime/datetime.module b/core/modules/datetime/datetime.module
index b545c36..4901ffd 100644
--- a/core/modules/datetime/datetime.module
+++ b/core/modules/datetime/datetime.module
@@ -1120,3 +1120,23 @@ function datetime_range_years($string, $date = NULL) {
   }
   return array($min_year, $max_year);
 }
+
+/**
+ * Implements hook_form_BASE_FORM_ID_alter() for node forms.
+ */
+function datetime_form_node_form_alter(&$form, &$form_state, $form_id) {
+  // Alter the 'Authored on' date to use datetime.
+  $form['author']['date']['#type'] = 'datetime';
+  $config = Drupal::config('system.date');
+  $format = $config->get('formats.html_date') . ' ' . $config->get('formats.html_time');
+  $form['author']['date']['#description'] = t('Format: %format. Leave blank to use the time of form submission.', array('%format' => datetime_format_example($format)));
+  unset($form['author']['date']['#maxlength']);
+}
+
+/**
+ * Implements hook_node_prepare().
+ */
+function datetime_node_prepare($node) {
+  // Prepare the 'Authored on' date to use datetime.
+  $node->date = new DrupalDateTime($node->created);
+}
diff --git a/core/modules/node/lib/Drupal/node/NodeFormController.php b/core/modules/node/lib/Drupal/node/NodeFormController.php
index 4bc59fe..63f2553 100644
--- a/core/modules/node/lib/Drupal/node/NodeFormController.php
+++ b/core/modules/node/lib/Drupal/node/NodeFormController.php
@@ -42,7 +42,7 @@ protected function prepareEntity() {
       $node->created = REQUEST_TIME;
     }
     else {
-      $node->date = new DrupalDateTime($node->created);
+      $node->date = format_date($node->created, 'custom', 'Y-m-d H:i:s O');
       // Remove the log message from the original node entity.
       $node->log = NULL;
     }
@@ -187,11 +187,11 @@ public function form(array $form, array &$form_state) {
       '#weight' => -1,
       '#description' => t('Leave blank for %anonymous.', array('%anonymous' => $user_config->get('anonymous'))),
     );
-    $format = variable_get('date_format_html_date', 'Y-m-d') . ' ' . variable_get('date_format_html_time', 'H:i:s');
     $form['author']['date'] = array(
-      '#type' => 'datetime',
+      '#type' => 'textfield',
       '#title' => t('Authored on'),
-      '#description' => t('Format: %format. Leave blank to use the time of form submission.', array('%format' => datetime_format_example($format))),
+      '#maxlength' => 25,
+      '#description' => t('Format: %time. The date format is YYYY-MM-DD and %timezone is the time zone offset from UTC. Leave blank to use the time of form submission.', array('%time' => !empty($node->date) ? date_format(date_create($node->date), 'Y-m-d H:i:s O') : format_date($node->created, 'custom', 'Y-m-d H:i:s O'), '%timezone' => !empty($node->date) ? date_format(date_create($node->date), 'O') : format_date($node->created, 'custom', 'O'))),
       '#default_value' => !empty($node->date) ? $node->date : '',
     );
 
@@ -333,7 +333,8 @@ public function validate(array $form, array &$form_state) {
 
     // Validate the "authored on" field.
     // The date element contains the date object.
-    if ($node->date instanceOf DrupalDateTime && $node->date->hasErrors()) {
+    $date = $node->date instanceof DrupalDateTime ? $node->date : new DrupalDateTime($node->date);
+    if ($date->hasErrors()) {
       form_set_error('date', t('You have to specify a valid date.'));
     }
 
diff --git a/core/modules/node/lib/Drupal/node/Tests/NodeTranslationUITest.php b/core/modules/node/lib/Drupal/node/Tests/NodeTranslationUITest.php
index 3632867..ac024bb 100644
--- a/core/modules/node/lib/Drupal/node/Tests/NodeTranslationUITest.php
+++ b/core/modules/node/lib/Drupal/node/Tests/NodeTranslationUITest.php
@@ -25,7 +25,7 @@ class NodeTranslationUITest extends EntityTranslationUITest {
    *
    * @var array
    */
-  public static $modules = array('language', 'translation_entity', 'node', 'field_ui');
+  public static $modules = array('language', 'translation_entity', 'node', 'datetime', 'field_ui');
 
   public static function getInfo() {
     return array(
diff --git a/core/modules/node/node.info.yml b/core/modules/node/node.info.yml
index 68681a8..777ec9e 100644
--- a/core/modules/node/node.info.yml
+++ b/core/modules/node/node.info.yml
@@ -5,5 +5,3 @@ package: Core
 version: VERSION
 core: 8.x
 configure: admin/structure/types
-dependencies:
-  - datetime
diff --git a/core/modules/node/node.install b/core/modules/node/node.install
index 2e761ae..d4ec353 100644
--- a/core/modules/node/node.install
+++ b/core/modules/node/node.install
@@ -808,11 +808,9 @@ function node_update_8013() {
 }
 
 /**
- * Enable Datetime module, which is now a required dependency.
+ * Empty update. See http://drupal.org/node/1836392.
  */
 function node_update_8014() {
-  // Enable the datetime module.
-  module_enable(array('datetime'));
 }
 
 /**
diff --git a/core/modules/system/lib/Drupal/system/Tests/Module/DependencyTest.php b/core/modules/system/lib/Drupal/system/Tests/Module/DependencyTest.php
index 023f485..96955cd 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Module/DependencyTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Module/DependencyTest.php
@@ -134,12 +134,12 @@ function testModuleEnableOrder() {
     $this->assertModules(array('module_test'), TRUE);
     \Drupal::state()->set('module_test.dependency', 'dependency');
     // module_test creates a dependency chain:
-    // - forum depends on taxonomy, comment, history, and ban (via module_test)
+    // - forum depends on taxonomy, comment, datetime, history, and ban (via module_test)
     // - taxonomy depends on options
     // - options depends on number
     // - ban depends on php (via module_test)
     // The correct enable order is:
-    $expected_order = array('php', 'ban', 'comment', 'history', 'number', 'options', 'taxonomy', 'forum');
+    $expected_order = array('php', 'ban', 'datetime', 'comment', 'history', 'number', 'options', 'taxonomy', 'forum');
 
     // Enable the modules through the UI, verifying that the dependency chain
     // is correct.
@@ -147,16 +147,17 @@ function testModuleEnableOrder() {
     $edit['modules[Core][forum][enable]'] = 'forum';
     $this->drupalPost('admin/modules', $edit, t('Save configuration'));
     $this->assertModules(array('forum'), FALSE);
-    $this->assertText(t('You must enable the History, Taxonomy, Options, Number, Comment, Ban, PHP Filter modules to install Forum.'));
+    $this->assertText(t('You must enable the History, Taxonomy, Options, Number, Comment, Datetime, Ban, PHP Filter modules to install Forum.'));
     $edit['modules[Core][history][enable]'] = 'history';
     $edit['modules[Core][options][enable]'] = 'options';
     $edit['modules[Core][number][enable]'] = 'number';
     $edit['modules[Core][taxonomy][enable]'] = 'taxonomy';
     $edit['modules[Core][comment][enable]'] = 'comment';
+    $edit['modules[Core][datetime][enable]'] = 'datetime';
     $edit['modules[Core][ban][enable]'] = 'ban';
     $edit['modules[Core][php][enable]'] = 'php';
     $this->drupalPost('admin/modules', $edit, t('Save configuration'));
-    $this->assertModules(array('forum', 'ban', 'php', 'comment', 'history', 'taxonomy', 'options', 'number'), TRUE);
+    $this->assertModules(array('forum', 'ban', 'php', 'datetime', 'comment', 'history', 'taxonomy', 'options', 'number'), TRUE);
 
     // Check the actual order which is saved by module_test_modules_enabled().
     $module_order = \Drupal::state()->get('system_test.module_enable_order') ?: array();