diff --git a/core/lib/Drupal/Core/Datetime/DateFormatter.php b/core/lib/Drupal/Core/Datetime/DateFormatter.php
index 073c956..34fcfa0 100644
--- a/core/lib/Drupal/Core/Datetime/DateFormatter.php
+++ b/core/lib/Drupal/Core/Datetime/DateFormatter.php
@@ -357,6 +357,7 @@ public function formatDiff($from, $to, $options = array()) {
     $interval = $date_time_to->diff($date_time_from);
 
     $granularity = $options['granularity'];
+    $parts = 0;
     $output = '';
 
     // We loop over the keys provided by \DateInterval explicitly. Since we
@@ -380,12 +381,21 @@ public function formatDiff($from, $to, $options = array()) {
             // ourselves.
             $interval_output = '';
             $days = $interval->d;
+            $weeks = floor($days / 7);
             if ($days >= 7) {
-              $weeks = floor($days / 7);
               $interval_output .= $this->formatPlural($weeks, '1 week', '@count weeks', array(), array('langcode' => $options['langcode']));
               $days -= $weeks * 7;
               $granularity--;
             }
+
+            // If months already were found and there are no weeks, explicitly
+            // break out of both the switch and the foreach loop to ensure only
+            // adjacent parts are added to the output. This avoids getting
+            // output like "1 month 1 day".
+            if($parts > 0 && $weeks == 0) {
+              break 2;
+            }
+
             if ($granularity > 0 && $days > 0) {
               $interval_output .= ($interval_output ? ' ' : '') . $this->formatPlural($days, '1 day', '@count days', array(), array('langcode' => $options['langcode']));
             }
@@ -406,6 +416,12 @@ public function formatDiff($from, $to, $options = array()) {
         }
         $output .= ($output ? ' ' : '') . $interval_output;
         $granularity--;
+        $parts++;
+      }
+      elseif ($parts) {
+        // 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;
       }
 
       if ($granularity == 0) {
diff --git a/core/tests/Drupal/Tests/Core/Datetime/DateTest.php b/core/tests/Drupal/Tests/Core/Datetime/DateTest.php
index 85e3ae4..e767914 100644
--- a/core/tests/Drupal/Tests/Core/Datetime/DateTest.php
+++ b/core/tests/Drupal/Tests/Core/Datetime/DateTest.php
@@ -310,8 +310,8 @@ public function providerTestFormatDiff() {
       // Checks for hours and possibly minutes or seconds.
       array('1 hour', $this->createTimestamp('2013-12-11 09:09:08'), $request_time),
       array('1 hour', $this->createTimestamp('2013-12-11 09:09:08'), $request_time),
-      array('1 hour 1 second', $this->createTimestamp('2013-12-11 09:09:07'), $request_time),
-      array('1 hour 2 seconds', $this->createTimestamp('2013-12-11 09:09:06'), $request_time),
+      array('1 hour', $this->createTimestamp('2013-12-11 09:09:07'), $request_time),
+      array('1 hour', $this->createTimestamp('2013-12-11 09:09:06'), $request_time),
       array('1 hour 1 minute', $this->createTimestamp('2013-12-11 09:08:08'), $request_time),
       array('1 hour 1 minute 1 second', $this->createTimestamp('2013-12-11 09:08:07'), $request_time, $granularity_3),
       array('1 hour 1 minute 2 seconds', $this->createTimestamp('2013-12-11 09:08:06'), $request_time, $granularity_4),
@@ -321,13 +321,13 @@ public function providerTestFormatDiff() {
 
       // Checks for days and possibly hours, minutes or seconds.
       array('1 day', $this->createTimestamp('2013-12-10 10:09:08'), $request_time),
-      array('1 day 1 second', $this->createTimestamp('2013-12-10 10:09:07'), $request_time),
+      array('1 day', $this->createTimestamp('2013-12-10 10:09:07'), $request_time),
       array('1 day 1 hour', $this->createTimestamp('2013-12-10 09:09:08'), $request_time),
       array('1 day 1 hour 1 minute', $this->createTimestamp('2013-12-10 09:08:07'), $request_time, $granularity_3 + $langcode_en),
       array('1 day 1 hour 1 minute 1 second', $this->createTimestamp('2013-12-10 09:08:07'), $request_time, $granularity_4 + $langcode_lolspeak),
       array('1 day 2 hours 2 minutes 2 seconds', $this->createTimestamp('2013-12-10 08:07:06'), $request_time, $granularity_4),
       array('2 days', $this->createTimestamp('2013-12-09 10:09:08'), $request_time),
-      array('2 days 2 minutes', $this->createTimestamp('2013-12-09 10:07:08'), $request_time),
+      array('2 days', $this->createTimestamp('2013-12-09 10:07:08'), $request_time),
       array('2 days 2 hours', $this->createTimestamp('2013-12-09 08:09:08'), $request_time),
       array('2 days 2 hours 2 minutes', $this->createTimestamp('2013-12-09 08:07:06'), $request_time, $granularity_3 + $langcode_en),
       array('2 days 2 hours 2 minutes 2 seconds', $this->createTimestamp('2013-12-09 08:07:06'), $request_time, $granularity_4 + $langcode_lolspeak),
@@ -343,33 +343,33 @@ public function providerTestFormatDiff() {
 
       // Checks for months and possibly days, hours, minutes or seconds.
       array('1 month', $this->createTimestamp('2013-11-11 10:09:08'), $request_time),
-      array('1 month 1 second', $this->createTimestamp('2013-11-11 10:09:07'), $request_time),
-      array('1 month 1 hour', $this->createTimestamp('2013-11-11 09:09:08'), $request_time),
-      array('1 month 1 hour 1 minute', $this->createTimestamp('2013-11-11 09:08:07'), $request_time, $granularity_3),
-      array('1 month 1 hour 1 minute 1 second', $this->createTimestamp('2013-11-11 09:08:07'), $request_time, $granularity_4),
+      array('1 month', $this->createTimestamp('2013-11-11 10:09:07'), $request_time),
+      array('1 month', $this->createTimestamp('2013-11-11 09:09:08'), $request_time),
+      array('1 month', $this->createTimestamp('2013-11-11 09:08:07'), $request_time, $granularity_3),
+      array('1 month', $this->createTimestamp('2013-11-11 09:08:07'), $request_time, $granularity_4),
       array('1 month 4 weeks', $this->createTimestamp('2013-10-13 10:09:08'), $request_time),
       array('1 month 4 weeks 1 day', $this->createTimestamp('2013-10-13 10:09:08'), $request_time, $granularity_3),
       array('1 month 4 weeks', $this->createTimestamp('2013-10-12 10:09:08'), $request_time),
       array('1 month 4 weeks 2 days', $this->createTimestamp('2013-10-12 10:09:08'), $request_time, $granularity_3),
       array('2 months', $this->createTimestamp('2013-10-11 10:09:08'), $request_time),
-      array('2 months 1 day', $this->createTimestamp('2013-10-10 10:09:08'), $request_time),
-      array('2 months 2 days', $this->createTimestamp('2013-10-09 08:07:06'), $request_time),
-      array('2 months 2 days 2 hours', $this->createTimestamp('2013-10-09 08:07:06'), $request_time, $granularity_3),
-      array('2 months 2 days 2 hours 2 minutes', $this->createTimestamp('2013-10-09 08:07:06'), $request_time, $granularity_4),
-      array('6 months 2 days', $this->createTimestamp('2013-06-09 10:09:08'), $request_time),
-      array('11 months 3 hours', $this->createTimestamp('2013-01-11 07:09:08'), $request_time),
+      array('2 months', $this->createTimestamp('2013-10-10 10:09:08'), $request_time),
+      array('2 months', $this->createTimestamp('2013-10-09 08:07:06'), $request_time),
+      array('2 months', $this->createTimestamp('2013-10-09 08:07:06'), $request_time, $granularity_3),
+      array('2 months', $this->createTimestamp('2013-10-09 08:07:06'), $request_time, $granularity_4),
+      array('6 months', $this->createTimestamp('2013-06-09 10:09:08'), $request_time),
+      array('11 months', $this->createTimestamp('2013-01-11 07:09:08'), $request_time),
       array('11 months 4 weeks', $this->createTimestamp('2012-12-12 10:09:08'), $request_time),
       array('11 months 4 weeks 2 days', $this->createTimestamp('2012-12-12 10:09:08'), $request_time, $granularity_3),
 
       // Checks for years and possibly months, days, hours, minutes or seconds.
       array('1 year', $this->createTimestamp('2012-12-11 10:09:08'), $request_time),
-      array('1 year 1 minute', $this->createTimestamp('2012-12-11 10:08:08'), $request_time),
-      array('1 year 1 day', $this->createTimestamp('2012-12-10 10:09:08'), $request_time),
+      array('1 year', $this->createTimestamp('2012-12-11 10:08:08'), $request_time),
+      array('1 year', $this->createTimestamp('2012-12-10 10:09:08'), $request_time),
       array('2 years', $this->createTimestamp('2011-12-11 10:09:08'), $request_time),
-      array('2 years 2 minutes', $this->createTimestamp('2011-12-11 10:07:08'), $request_time),
-      array('2 years 2 days', $this->createTimestamp('2011-12-09 10:09:08'), $request_time),
-      array('2 years 2 months 2 days', $this->createTimestamp('2011-10-09 08:07:06'), $request_time, $granularity_3),
-      array('2 years 2 months 2 days 2 hours', $this->createTimestamp('2011-10-09 08:07:06'), $request_time, $granularity_4),
+      array('2 years', $this->createTimestamp('2011-12-11 10:07:08'), $request_time),
+      array('2 years', $this->createTimestamp('2011-12-09 10:09:08'), $request_time),
+      array('2 years 2 months', $this->createTimestamp('2011-10-09 08:07:06'), $request_time, $granularity_3),
+      array('2 years 2 months', $this->createTimestamp('2011-10-09 08:07:06'), $request_time, $granularity_4),
       array('10 years', $this->createTimestamp('2003-12-11 10:09:08'), $request_time),
       array('100 years', $this->createTimestamp('1913-12-11 10:09:08'), $request_time),