diff --git a/core/modules/datetime/src/Plugin/Field/FieldType/DateTimeItem.php b/core/modules/datetime/src/Plugin/Field/FieldType/DateTimeItem.php
index a7dd1c3..404cef0 100644
--- a/core/modules/datetime/src/Plugin/Field/FieldType/DateTimeItem.php
+++ b/core/modules/datetime/src/Plugin/Field/FieldType/DateTimeItem.php
@@ -33,6 +33,7 @@ class DateTimeItem extends FieldItemBase {
   public static function defaultStorageSettings() {
     return array(
       'datetime_type' => 'datetime',
+      'timezone_handling' => 'site',
     ) + parent::defaultStorageSettings();
   }
 
@@ -61,6 +62,10 @@ public static function propertyDefinitions(FieldStorageDefinitionInterface $fiel
       ->setClass('\Drupal\datetime\DateTimeComputed')
       ->setSetting('date source', 'value');
 
+    // @todo Shouldn't this only be needed if `$field_definition->getSetting('timezone_handling') === TRUE`?
+    $properties['timezone'] = DataDefinition::create('string')
+      ->setLabel(t('Timezone'));
+
     return $properties;
   }
 
@@ -68,7 +73,7 @@ public static function propertyDefinitions(FieldStorageDefinitionInterface $fiel
    * {@inheritdoc}
    */
   public static function schema(FieldStorageDefinitionInterface $field_definition) {
-    return array(
+    $schema = array(
       'columns' => array(
         'value' => array(
           'description' => 'The date value.',
@@ -80,6 +85,17 @@ public static function schema(FieldStorageDefinitionInterface $field_definition)
         'value' => array('value'),
       ),
     );
+
+    // Store the timezone if timezone handling is per-date.
+    if ($field_definition->getSetting('timezone_handling') === 'date') {
+      $schema['columns']['timezone'] = array(
+        'description' => 'The date timezone',
+        'type' => 'varchar',
+        'length' => 50,
+      );
+    }
+
+    return $schema;
   }
 
   /**
@@ -99,6 +115,20 @@ public function storageSettingsForm(array &$form, FormStateInterface $form_state
       ),
     );
 
+    $element['timezone_handling'] = array(
+      '#type' => 'select',
+      '#title' => t('Timezone handling'),
+      '#options' => array(
+        'site' => t("Site's timezone"),
+        'date' => t("Date's timezone"),
+        'user' => t("User's timezone"),
+        'utc' => 'UTC',
+        'none' => t('No timezone conversion'),
+      ),
+      '#default_value' => $this->getSetting('timezone_handling'),
+      '#required' => TRUE,
+    );
+
     return $element;
   }
 
diff --git a/core/modules/datetime/src/Plugin/Field/FieldWidget/DateTimeWidgetBase.php b/core/modules/datetime/src/Plugin/Field/FieldWidget/DateTimeWidgetBase.php
index dfe750e..8c3dcee 100644
--- a/core/modules/datetime/src/Plugin/Field/FieldWidget/DateTimeWidgetBase.php
+++ b/core/modules/datetime/src/Plugin/Field/FieldWidget/DateTimeWidgetBase.php
@@ -39,6 +39,15 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
       '#required' => $element['#required'],
     );
 
+    if ($this->getFieldSetting('timezone_handling') === 'date') {
+      $element['timezone'] = array(
+        '#type' => 'select',
+        '#options' => \DateTimeZone::listIdentifiers(),
+        // Default to user's timezone.
+        '#default_value' => drupal_get_user_timezone(),
+      );
+    }
+
     if ($items[$delta]->date) {
       $date = $items[$delta]->date;
       // The date was created and verified during field_load(), so it is safe to