diff --git a/planetstack/core/models/billing.py b/planetstack/core/models/billing.py
index 6d1c331..8c61418 100644
--- a/planetstack/core/models/billing.py
+++ b/planetstack/core/models/billing.py
@@ -6,6 +6,7 @@
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.contenttypes import generic
 from django.db.models import Sum
+from django.utils import timezone
 
 class Account(PlCoreBase):
     site = models.ForeignKey(Site, related_name="accounts", help_text="Site for this account")
@@ -51,7 +52,7 @@
 class Payment(PlCoreBase):
     account = models.ForeignKey(Account, related_name="payments")
     amount = models.FloatField(default=0.0)
-    date = models.DateTimeField(default=datetime.datetime.now)
+    date = models.DateTimeField(default=timezone.now)
 
     def __unicode__(self): return u'%s-%0.2f-%s' % (self.account.site.name, self.amount, str(self.date))
 
diff --git a/planetstack/core/models/plcorebase.py b/planetstack/core/models/plcorebase.py
index d1784cd..d461c9d 100644
--- a/planetstack/core/models/plcorebase.py
+++ b/planetstack/core/models/plcorebase.py
@@ -1,10 +1,10 @@
-import datetime
 import os
 import sys
 from django.db import models
 from django.forms.models import model_to_dict
 from django.core.urlresolvers import reverse
 from django.forms.models import model_to_dict
+from django.utils import timezone
 import model_policy
 
 try:
@@ -23,9 +23,13 @@
 # the core model is abstract.
 class PlCoreBaseDeletionManager(models.Manager):
     def get_queryset(self):
-        return super(PlCoreBaseDeletionManager, self).get_query_set().filter(deleted=True)
+        parent=super(PlCoreBaseDeletionManager, self)
+        if hasattr(parent, "get_queryset"):
+            return parent.get_queryset().filter(deleted=True)
+        else:
+            return parent.get_query_set().filter(deleted=True)
 
-    # deprecated in django 1.7 in favor of get_queryset()
+    # deprecated in django 1.7 in favor of get_queryset().
     def get_query_set(self):
         return self.get_queryset()
 
@@ -33,9 +37,13 @@
 # the core model is abstract.
 class PlCoreBaseManager(models.Manager):
     def get_queryset(self):
-        return super(PlCoreBaseManager, self).get_query_set().filter(deleted=False)
+        parent=super(PlCoreBaseManager, self)
+        if hasattr(parent, "get_queryset"):
+            return parent.get_queryset().filter(deleted=False)
+        else:
+            return parent.get_query_set().filter(deleted=False)
 
-    # deprecated in django 1.7 in favor of get_queryset()
+    # deprecated in django 1.7 in favor of get_queryset().
     def get_query_set(self):
         return self.get_queryset()
 
@@ -45,8 +53,8 @@
 
     # default values for created and updated are only there to keep evolution
     # from failing.
-    created = models.DateTimeField(auto_now_add=True, default=datetime.datetime.now)
-    updated = models.DateTimeField(auto_now=True, default=datetime.datetime.now)
+    created = models.DateTimeField(auto_now_add=True, default=timezone.now)
+    updated = models.DateTimeField(auto_now=True, default=timezone.now)
     enacted = models.DateTimeField(null=True, default=None)
     backend_status = models.CharField(max_length=140,
                                       default="Provisioning in progress")