diff --git a/module/metric/calc.class.php b/module/metric/calc.class.php
index aeab8ae893..997c32105f 100644
--- a/module/metric/calc.class.php
+++ b/module/metric/calc.class.php
@@ -297,7 +297,7 @@ class baseCalc
         if(strlen($dateStr) > 10) $dateStr = substr($dateStr, 0, 10);
         $date = DateTime::createFromFormat('Y-m-d', $dateStr);
 
-        return $date->format('W');
+        return substr($date->format('oW'), -2);
     }
 
     /**
diff --git a/module/metric/model.php b/module/metric/model.php
index eb585077d5..4cce26b098 100755
--- a/module/metric/model.php
+++ b/module/metric/model.php
@@ -1914,6 +1914,7 @@ class metricModel extends model
         $month = date('m', $timestamp);
         $day   = date('d', $timestamp);
         $week  = date('oW', $timestamp);
+        $week  = substr($week, -2);
 
         $dateValues = new stdClass();
 
diff --git a/module/metric/zen.php b/module/metric/zen.php
index f37a29be52..f788e07678 100644
--- a/module/metric/zen.php
+++ b/module/metric/zen.php
@@ -179,7 +179,7 @@ class metricZen extends metric
      */
     protected function prepareMetricRecord($calcList)
     {
-        $options = array('year' => date('Y'), 'month' => date('n'), 'week' => date('W'), 'day' => date('j'));
+        $options = array('year' => date('Y'), 'month' => date('n'), 'week' => substr(date('oW'), -2), 'day' => date('j'));
 
         $now        = helper::now();
         $dateValues = $this->metric->generateDateValues($now);