diff --git a/core/lib/Drupal/Core/Datetime/DateFormatter.php b/core/lib/Drupal/Core/Datetime/DateFormatter.php
index 02e8b92..a8b1338 100644
--- a/core/lib/Drupal/Core/Datetime/DateFormatter.php
+++ b/core/lib/Drupal/Core/Datetime/DateFormatter.php
@@ -196,7 +196,6 @@ public function format($timestamp, $type = 'medium', $format = '', $timezone = N
    * @see \Drupal\Core\Datetime\DateFormatter::formatDiff()
    */
   public function formatInterval($interval, $granularity = 2, $langcode = NULL) {
-    $parts = 0;
     $output = '';
     foreach ($this->units as $key => $value) {
       $key = explode('|', $key);
@@ -204,9 +203,8 @@ public function formatInterval($interval, $granularity = 2, $langcode = NULL) {
         $output .= ($output ? ' ' : '') . $this->formatPlural(floor($interval / $value), $key[0], $key[1], array(), array('langcode' => $langcode));
         $interval %= $value;
         $granularity--;
-        $parts++;
       }
-      elseif ($parts) {
+      elseif ($output) {
         // Break if there was previous output but not any output at this level,
         // to avoid skipping levels and getting output like "1 year 1 second".
         break;
@@ -390,6 +388,11 @@ public function formatDiff($from, $to, $options = array()) {
             if ((!$output || $weeks > 0) && $granularity > 0 && $days > 0) {
               $interval_output .= ($interval_output ? ' ' : '') . $this->formatPlural($days, '1 day', '@count days', array(), array('langcode' => $options['langcode']));
             }
+            else {
+              // If we have months but no weeks, explicitly set granularity to
+              // zero so we don't get output like "1 day 1 hour".
+              $granularity = 0;
+            }
             break;
 
           case 'h':