diff --git a/ara/api/serializers.py b/ara/api/serializers.py
index <HASH>..<HASH> 100644
--- a/ara/api/serializers.py
+++ b/ara/api/serializers.py
@@ -20,7 +20,6 @@ import json
 import logging
 import zlib
 
-from django.utils import timezone
 from rest_framework import serializers
 
 from ara.api import models
@@ -70,7 +69,7 @@ class DurationSerializer(serializers.ModelSerializer):
     @staticmethod
     def get_duration(obj):
         if obj.ended is None:
-            return timezone.now() - obj.started
+            return obj.updated - obj.started
         return obj.ended - obj.started
Use playbook.updated instead of "now" for calculating duration

Using now() to calculate the duration was not accurate.
If a playbook had never ended, it would show that a playbook ran
yesterday for ><I>k seconds and keep growing, for example.
playbook.updated is the next best thing we've got so let's use that.

Change-Id: I<I>c<I>d<I>e0a<I>f3da1dcbf<I>c7e8