diff --git a/core/config/schema/core.entity.schema.yml b/core/config/schema/core.entity.schema.yml
index 8a15a4c..e4821c4 100644
--- a/core/config/schema/core.entity.schema.yml
+++ b/core/config/schema/core.entity.schema.yml
@@ -322,9 +322,12 @@ field.formatter.settings.timestamp_ago:
   type: mapping
   label: 'Timestamp ago display format settings'
   mapping:
-    date_format:
+    future_format:
       type: string
-      label: 'Date format'
+      label: 'Future format'
+    past_format:
+      type: string
+      label: 'Past format'
     granularity:
       type: integer
       label: 'Granularity'
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/TimestampAgoFormatter.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/TimestampAgoFormatter.php
index 34cf92c..70f6636 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/TimestampAgoFormatter.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/TimestampAgoFormatter.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\Core\Field\Plugin\Field\FieldFormatter;
 
+use Drupal\Component\Utility\SafeMarkup;
 use Drupal\Core\Datetime\DateFormatter;
 use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\FieldItemListInterface;
@@ -14,6 +15,7 @@
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\HttpFoundation\Request;
 
 /**
  * Plugin implementation of the 'timestamp' formatter as time ago.
@@ -38,6 +40,13 @@ class TimestampAgoFormatter extends FormatterBase implements ContainerFactoryPlu
   protected $dateFormatter;
 
   /**
+    * The current Request object.
+    *
+    * @var \Symfony\Component\HttpFoundation\Request
+    */
+  protected $request;
+
+  /**
    * Constructs a TimestampAgoFormatter object.
    *
    * @param string $plugin_id
@@ -56,11 +65,14 @@ class TimestampAgoFormatter extends FormatterBase implements ContainerFactoryPlu
    *   Any third party settings.
    * @param \Drupal\Core\Datetime\DateFormatter $date_formatter
    *   The date formatter service.
+   * @param \Symfony\Component\HttpFoundation\Request $request
+   *   The current request.
    */
-  public function __construct($plugin_id, $plugin_definition, FieldDefinitionInterface $field_definition, array $settings, $label, $view_mode, array $third_party_settings, DateFormatter $date_formatter) {
+  public function __construct($plugin_id, $plugin_definition, FieldDefinitionInterface $field_definition, array $settings, $label, $view_mode, array $third_party_settings, DateFormatter $date_formatter, Request $request) {
     parent::__construct($plugin_id, $plugin_definition, $field_definition, $settings, $label, $view_mode, $third_party_settings);
 
     $this->dateFormatter = $date_formatter;
+    $this->request = $request;
   }
 
   /**
@@ -76,7 +88,8 @@ public static function create(ContainerInterface $container, array $configuratio
       $configuration['label'],
       $configuration['view_mode'],
       $configuration['third_party_settings'],
-      $container->get('date.formatter')
+      $container->get('date.formatter'),
+      $container->get('request_stack')->getCurrentRequest()
     );
   }
 
@@ -85,7 +98,8 @@ public static function create(ContainerInterface $container, array $configuratio
    */
   public static function defaultSettings() {
     return array(
-      'date_format' => 'raw time ago',
+      'future_format' => '@time hence',
+      'past_format' => '@time ago',
       'granularity' => 2,
     ) + parent::defaultSettings();
   }
@@ -96,25 +110,24 @@ public static function defaultSettings() {
   public function settingsForm(array $form, FormStateInterface $form_state) {
     $elements = parent::settingsForm($form, $form_state);
 
-    $elements['date_format'] = array(
-      '#type' => 'select',
-      '#title' => $this->t('Date format'),
-      '#options' => array(
-        'raw time ago' => $this->t('Time ago'),
-        'time ago' => $this->t('Time ago (with "ago" appended)'),
-        'raw time hence' => $this->t('Time hence'),
-        'time hence' => $this->t('Time hence (with "hence" appended)'),
-        'raw time span' => $this->t('Time span (future dates have "-" prepended)'),
-        'inverse time span' => $this->t('Time span (past dates have "-" prepended)'),
-        'time span' => $this->t('Time span (with "ago/hence" appended)'),
-      ),
-      '#default_value' => $this->getSetting('date_format') ?: 'raw time ago',
+    $form['future_format'] = array(
+      '#type' => 'textfield',
+      '#title' => $this->t('Future format'),
+      '#default_value' => $this->getSetting('future_format'),
+      '#description' => $this->t('The format for timestamps in the future. Use <em>@time</em> where you want the time to appear.'),
+    );
+
+    $form['past_format'] = array(
+      '#type' => 'textfield',
+      '#title' => $this->t('Past format'),
+      '#default_value' => $this->getSetting('past_format'),
+      '#description' => $this->t('The format for timestamps in the past. Use <em>@time</em> where you want the time to appear.'),
     );
 
     $elements['granularity'] = array(
       '#type' => 'number',
       '#title' => $this->t('Granularity'),
-      '#description' => $this->t('How many time units should be shown in the "time ago" string.'),
+      '#description' => $this->t('How many time units should be shown in the formatted output.'),
       '#default_value' => $this->getSetting('granularity') ?: 2,
       '#min' => 1,
       '#max' => 7,
@@ -129,8 +142,10 @@ public function settingsForm(array $form, FormStateInterface $form_state) {
   public function settingsSummary() {
     $summary = parent::settingsSummary();
 
-    $summary[] = $this->t('Date format: @date_format', array('@date_format' => $this->getSetting('date_format')));
-    $summary[] = $this->t('Granularity: @granularity', array('@granularity' => $this->getSetting('granularity')));
+    $future_date = strtotime('1 year 1 month 1 week 1 day 1 hour 1 minute');
+    $past_date = strtotime('-1 year -1 month -1 week -1 day -1 hour -1 minute');
+    $summary[] = t('Future date: %display', array('%display' => $this->formatTimestamp($future_date)));
+    $summary[] = t('Past date: %display', array('%display' => $this->formatTimestamp($past_date)));
 
     return $summary;
   }
@@ -143,34 +158,7 @@ public function viewElements(FieldItemListInterface $items) {
 
     foreach ($items as $delta => $item) {
       if ($item->value) {
-        $format = $this->getSetting('date_format');
-        $granularity = $this->getSetting('granularity');
-        // Will be positive for a datetime in the past (ago), and negative for a datetime in the future (hence).
-        $time_diff = REQUEST_TIME - $item->value;
-        switch ($format) {
-          case 'time ago':
-            $updated = $this->t('%time ago', array('%time' => $this->dateFormatter->formatInterval($time_diff, $granularity)));
-            break;
-          case 'raw time hence':
-            $updated = $this->dateFormatter->formatInterval(-$time_diff, $granularity);
-            break;
-          case 'time hence':
-            $updated = $this->t('%time hence', array('%time' => $this->dateFormatter->formatInterval(-$time_diff, $granularity)));
-            break;
-          case 'raw time span':
-            $updated = ($time_diff < 0 ? '-' : '') . $this->dateFormatter->formatInterval(abs($time_diff), $granularity);
-            break;
-          case 'inverse time span':
-            $updated = ($time_diff > 0 ? '-' : '') . $this->dateFormatter->formatInterval(abs($time_diff), $granularity);
-            break;
-          case 'time span':
-            $updated = $this->t(($time_diff < 0 ? '%time hence' : '%time ago'), array('%time' => $this->dateFormatter->formatInterval(abs($time_diff), $granularity)));
-            break;
-          case 'raw time ago':
-          default:
-            $updated = $this->dateFormatter->formatInterval($time_diff, $granularity);
-            break;
-        }
+        $updated = $this->formatTimestamp($item->value);
       }
       else {
         $updated = $this->t('never');
@@ -182,4 +170,31 @@ public function viewElements(FieldItemListInterface $items) {
     return $elements;
   }
 
+  /**
+    * Creates a formatted timestamp value as a string.
+    *
+    * @todo Refactor when https://www.drupal.org/node/2456521 is committed.
+    *
+    * @param int $timestamp
+    *   A UNIX timestamp to format.
+    *
+    * @return string
+    *   The formatted timestamp string using the past or future format setting.
+    */
+  protected function formatTimestamp($timestamp) {
+    $granularity = $this->getSetting('granularity');
+    // Will be positive for a timestamp in the past (ago), and negative for a datetime in the future (hence).
+
+    $interval = $this->request->server->get('REQUEST_TIME') - $timestamp;
+
+    if ($interval > 0) {
+      return SafeMarkup::format($this->getSetting('past_format'), ['@time' => $this->dateFormatter->formatInterval($interval, $granularity)]);
+    }
+    else {
+      // DateFormatter::formatInterval() assumes positive intervals, so negate
+      // it to force the calculation to work properly.
+      return SafeMarkup::format($this->getSetting('future_format'), ['@time' => $this->dateFormatter->formatInterval(-$interval, $granularity)]);
+    }
+  }
+
 }
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/TimestampFormatter.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/TimestampFormatter.php
index cffc141..f5515c0 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/TimestampFormatter.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/TimestampFormatter.php
@@ -39,14 +39,14 @@ class TimestampFormatter extends FormatterBase implements ContainerFactoryPlugin
   protected $dateFormatter;
 
   /**
-   * The date storage.
+   * The date format entity storage.
    *
    * @var \Drupal\Core\Entity\EntityStorageInterface
    */
-  protected $dateStorage;
+  protected $dateFormatStorage;
 
   /**
-   * Constructs a new DateTimeDefaultFormatter.
+   * Constructs a new TimestampFormatter.
    *
    * @param string $plugin_id
    *   The plugin_id for the formatter.
@@ -64,14 +64,14 @@ class TimestampFormatter extends FormatterBase implements ContainerFactoryPlugin
    *   Third party settings.
    * @param \Drupal\Core\Datetime\DateFormatter $date_formatter
    *   The date formatter service.
-   * @param \Drupal\Core\Entity\EntityStorageInterface $date_storage
+   * @param \Drupal\Core\Entity\EntityStorageInterface $date_format_storage
    *   The date storage.
    */
-  public function __construct($plugin_id, $plugin_definition, FieldDefinitionInterface $field_definition, array $settings, $label, $view_mode, array $third_party_settings, DateFormatter $date_formatter, EntityStorageInterface $date_storage) {
+  public function __construct($plugin_id, $plugin_definition, FieldDefinitionInterface $field_definition, array $settings, $label, $view_mode, array $third_party_settings, DateFormatter $date_formatter, EntityStorageInterface $date_format_storage) {
     parent::__construct($plugin_id, $plugin_definition, $field_definition, $settings, $label, $view_mode, $third_party_settings);
 
     $this->dateFormatter = $date_formatter;
-    $this->dateStorage = $date_storage;
+    $this->dateFormatStorage = $date_format_storage;
   }
 
   /**
@@ -110,7 +110,7 @@ public function settingsForm(array $form, FormStateInterface $form_state) {
 
     $date_formats = array();
 
-    foreach ($this->dateStorage->loadMultiple() as $machine_name => $value) {
+    foreach ($this->dateFormatStorage->loadMultiple() as $machine_name => $value) {
       $date_formats[$machine_name] = $this->t('@name format: @date', array('@name' => $value->label(), '@date' => $this->dateFormatter->format(REQUEST_TIME, $machine_name)));
     }
 
@@ -136,9 +136,9 @@ public function settingsForm(array $form, FormStateInterface $form_state) {
 
     $elements['timezone'] = array(
       '#type' => 'select',
-      '#title' => $this->t('Timezone'),
-      '#description' => $this->t('Timezone to be used for date output.'),
-      '#options' => array('' => $this->t('- Default site/user timezone -')) + system_time_zones(FALSE),
+      '#title' => $this->t('Time zone'),
+      '#description' => $this->t('Time zone to be used for date output.'),
+      '#options' => array('' => $this->t('- Default site/user time zone -')) + system_time_zones(FALSE),
       '#default_value' => $this->getSetting('timezone'),
     );
 
@@ -153,7 +153,7 @@ public function settingsSummary() {
 
     $summary[] = $this->t('Date format: @date_format', array('@date_format' => $this->getSetting('date_format')));
     $summary[] = $this->t('Custom date format: @custom_date_format', array('@custom_date_format' => $this->getSetting('custom_date_format')));
-    $summary[] = $this->t('Timezone: @timezone', array('@timezone' => $this->getSetting('timezone')));
+    $summary[] = $this->t('Time zone: @timezone', array('@timezone' => $this->getSetting('timezone')));
 
     return $summary;
   }