diff --git a/common/djangoapps/enrollment/tests/test_views.py b/common/djangoapps/enrollment/tests/test_views.py
index ac77ab6883..98ad08336e 100644
--- a/common/djangoapps/enrollment/tests/test_views.py
+++ b/common/djangoapps/enrollment/tests/test_views.py
@@ -454,9 +454,9 @@ class EnrollmentTest(EnrollmentTestMixin, ModuleStoreTestCase, APITestCase, Ente
         # enforced at the data layer, so we need to handle the case
         # in which no dates are specified.
         (None, None, None, None),
-        (datetime.datetime(2015, 1, 2, 3, 4, 5), None, "2015-01-02T03:04:05Z", None),
-        (None, datetime.datetime(2015, 1, 2, 3, 4, 5), None, "2015-01-02T03:04:05Z"),
-        (datetime.datetime(2014, 6, 7, 8, 9, 10), datetime.datetime(2015, 1, 2, 3, 4, 5), "2014-06-07T08:09:10Z", "2015-01-02T03:04:05Z"),
+        (datetime.datetime(2015, 1, 2, 3, 4, 5, tzinfo=pytz.UTC), None, "2015-01-02T03:04:05Z", None),
+        (None, datetime.datetime(2015, 1, 2, 3, 4, 5, tzinfo=pytz.UTC), None, "2015-01-02T03:04:05Z"),
+        (datetime.datetime(2014, 6, 7, 8, 9, 10, tzinfo=pytz.UTC), datetime.datetime(2015, 1, 2, 3, 4, 5, tzinfo=pytz.UTC), "2014-06-07T08:09:10Z", "2015-01-02T03:04:05Z"),
     )
     @ddt.unpack
     def test_get_course_details_course_dates(self, start_datetime, end_datetime, expected_start, expected_end):
@@ -579,7 +579,7 @@ class EnrollmentTest(EnrollmentTestMixin, ModuleStoreTestCase, APITestCase, Ente
             course_id=self.course.id,
             mode_slug=CourseMode.VERIFIED,
             mode_display_name=CourseMode.VERIFIED,
-            expiration_datetime='1970-01-01 05:00:00'
+            expiration_datetime='1970-01-01 05:00:00Z'
         )
 
         # Passes the include_expired parameter to the API call
diff --git a/common/djangoapps/entitlements/api/v1/tests/test_views.py b/common/djangoapps/entitlements/api/v1/tests/test_views.py
index 2b69196597..c57f177ec2 100644
--- a/common/djangoapps/entitlements/api/v1/tests/test_views.py
+++ b/common/djangoapps/entitlements/api/v1/tests/test_views.py
@@ -2,11 +2,11 @@ import json
 import logging
 import unittest
 import uuid
-from datetime import datetime, timedelta
+from datetime import timedelta
 
-import pytz
 from django.conf import settings
 from django.core.urlresolvers import reverse
+from django.utils.timezone import now
 
 from course_modes.models import CourseMode
 from course_modes.tests.factories import CourseModeFactory
@@ -41,7 +41,7 @@ class EntitlementViewSetTest(ModuleStoreTestCase):
             course_id=self.course.id,
             mode_slug=CourseMode.VERIFIED,
             # This must be in the future to ensure it is returned by downstream code.
-            expiration_datetime=datetime.now(pytz.UTC) + timedelta(days=1)
+            expiration_datetime=now() + timedelta(days=1)
         )
 
         self.entitlements_list_url = reverse('entitlements_api:v1:entitlements-list')
@@ -216,11 +216,11 @@ class EntitlementViewSetTest(ModuleStoreTestCase):
         assert results == CourseEntitlementSerializer([entitlement], many=True).data
 
     def test_staff_get_expired_entitlements(self):
-        past_datetime = datetime.utcnow().replace(tzinfo=pytz.UTC) - timedelta(days=365 * 2)
+        past_datetime = now() - timedelta(days=365 * 2)
         entitlements = CourseEntitlementFactory.create_batch(2, created=past_datetime, user=self.user)
 
         # Set the first entitlement to be at a time that it isn't expired
-        entitlements[0].created = datetime.utcnow()
+        entitlements[0].created = now()
         entitlements[0].save()
 
         response = self.client.get(
@@ -233,7 +233,7 @@ class EntitlementViewSetTest(ModuleStoreTestCase):
         assert results[0].get('expired_at') is None and results[1].get('expired_at') is None
 
     def test_get_user_expired_entitlements(self):
-        past_datetime = datetime.utcnow().replace(tzinfo=pytz.UTC) - timedelta(days=365 * 2)
+        past_datetime = now() - timedelta(days=365 * 2)
         not_staff_user = UserFactory()
         self.client.login(username=not_staff_user.username, password=TEST_PASSWORD)
         entitlement_user2 = CourseEntitlementFactory.create_batch(2, user=not_staff_user, created=past_datetime)
@@ -241,7 +241,7 @@ class EntitlementViewSetTest(ModuleStoreTestCase):
         url += '?user={username}'.format(username=not_staff_user.username)
 
         # Set the first entitlement to be at a time that it isn't expired
-        entitlement_user2[0].created = datetime.utcnow()
+        entitlement_user2[0].created = now()
         entitlement_user2[0].save()
 
         response = self.client.get(
@@ -284,7 +284,7 @@ class EntitlementViewSetTest(ModuleStoreTestCase):
         assert results == CourseEntitlementSerializer(entitlement).data and results.get('expired_at') is None
 
     def test_get_expired_entitlement_by_uuid(self):
-        past_datetime = datetime.utcnow().replace(tzinfo=pytz.UTC) - timedelta(days=365 * 2)
+        past_datetime = now() - timedelta(days=365 * 2)
         entitlement = CourseEntitlementFactory(created=past_datetime)
         CourseEntitlementFactory.create_batch(2)
 
diff --git a/common/djangoapps/entitlements/models.py b/common/djangoapps/entitlements/models.py
index 80e74fc5a4..735933bf79 100644
--- a/common/djangoapps/entitlements/models.py
+++ b/common/djangoapps/entitlements/models.py
@@ -1,11 +1,11 @@
 import uuid as uuid_tools
-from datetime import datetime, timedelta
+from datetime import timedelta
 from util.date_utils import strftime_localized
 
-import pytz
 from django.conf import settings
 from django.contrib.sites.models import Site
 from django.db import models
+from django.utils.timezone import now
 
 from certificates.models import GeneratedCertificate
 from model_utils.models import TimeStampedModel
@@ -45,16 +45,16 @@ class CourseEntitlementPolicy(models.Model):
         Returns an integer of number of days until the entitlement expires.
         Includes the logic for regaining an entitlement.
         """
-        now = datetime.now(tz=pytz.UTC)
+        now_timestamp = now()
         expiry_date = entitlement.created + self.expiration_period
-        days_until_expiry = (expiry_date - now).days
+        days_until_expiry = (expiry_date - now_timestamp).days
         if not entitlement.enrollment_course_run:
             return days_until_expiry
         course_overview = CourseOverview.get_from_id(entitlement.enrollment_course_run.course_id)
         # Compute the days left for the regain
-        days_since_course_start = (now - course_overview.start).days
-        days_since_enrollment = (now - entitlement.enrollment_course_run.created).days
-        days_since_entitlement_created = (now - entitlement.created).days
+        days_since_course_start = (now_timestamp - course_overview.start).days
+        days_since_enrollment = (now_timestamp - entitlement.enrollment_course_run.created).days
+        days_since_entitlement_created = (now_timestamp - entitlement.created).days
 
         # We want to return whichever days value is less since it is then the more recent one
         days_until_regain_ends = (self.regain_period.days -  # pylint: disable=no-member
@@ -184,8 +184,7 @@ class CourseEntitlement(TimeStampedModel):
         """
         Returns an integer of number of days since the entitlement has been created
         """
-        utc = pytz.UTC
-        return (datetime.now(tz=utc) - self.created).days
+        return (now() - self.created).days
 
     def update_expired_at(self):
         """
@@ -195,7 +194,7 @@ class CourseEntitlement(TimeStampedModel):
         if not self.expired_at:
             if (self.policy.get_days_until_expiration(self) < 0 or
                     (self.enrollment_course_run and not self.is_entitlement_regainable())):
-                self.expired_at = datetime.utcnow()
+                self.expired_at = now()
                 self.save()
 
     def get_days_until_expiration(self):
@@ -235,7 +234,7 @@ class CourseEntitlement(TimeStampedModel):
         expiration_date = None
         if self.get_days_until_expiration() < settings.ENTITLEMENT_EXPIRED_ALERT_PERIOD:
             expiration_date = strftime_localized(
-                datetime.now(tz=pytz.UTC) + timedelta(days=self.get_days_until_expiration()),
+                now() + timedelta(days=self.get_days_until_expiration()),
                 'SHORT_DATE'
             )
         expired_at = strftime_localized(self.expired_at_datetime, 'SHORT_DATE') if self.expired_at_datetime else None
diff --git a/common/djangoapps/entitlements/tests/test_models.py b/common/djangoapps/entitlements/tests/test_models.py
index 98f5b9a3e6..e191f29aba 100644
--- a/common/djangoapps/entitlements/tests/test_models.py
+++ b/common/djangoapps/entitlements/tests/test_models.py
@@ -1,11 +1,11 @@
 """Test Entitlements models"""
 
 import unittest
-from datetime import datetime, timedelta
+from datetime import timedelta
 
-import pytz
 from django.conf import settings
 from django.test import TestCase
+from django.utils.timezone import now
 
 from certificates.models import CertificateStatuses  # pylint: disable=import-error
 from lms.djangoapps.certificates.api import MODES
@@ -25,7 +25,7 @@ class TestModels(TestCase):
     def setUp(self):
         super(TestModels, self).setUp()
         self.course = CourseOverviewFactory.create(
-            start=datetime.utcnow()
+            start=now()
         )
         self.enrollment = CourseEnrollmentFactory.create(course_id=self.course.id)
 
@@ -40,13 +40,13 @@ class TestModels(TestCase):
         assert entitlement.is_entitlement_redeemable() is True
 
         # Create a date 2 years in the past (greater than the policy expire period of 450 days)
-        past_datetime = datetime.utcnow().replace(tzinfo=pytz.UTC) - timedelta(days=365 * 2)
+        past_datetime = now() - timedelta(days=365 * 2)
         entitlement.created = past_datetime
         entitlement.save()
 
         assert entitlement.is_entitlement_redeemable() is False
 
-        entitlement = CourseEntitlementFactory.create(expired_at=datetime.now())
+        entitlement = CourseEntitlementFactory.create(expired_at=now())
 
         assert entitlement.is_entitlement_refundable() is False
 
@@ -64,7 +64,7 @@ class TestModels(TestCase):
         assert entitlement.is_entitlement_refundable() is False
 
         # Create a date 70 days in the past (greater than the policy refund expire period of 60 days)
-        past_datetime = datetime.utcnow().replace(tzinfo=pytz.UTC) - timedelta(days=70)
+        past_datetime = now() - timedelta(days=70)
         entitlement = CourseEntitlementFactory.create(created=past_datetime)
 
         assert entitlement.is_entitlement_refundable() is False
@@ -72,7 +72,7 @@ class TestModels(TestCase):
         entitlement = CourseEntitlementFactory.create(enrollment_course_run=self.enrollment)
         # Create a date 20 days in the past (less than the policy refund expire period of 60 days)
         # but more than the policy regain period of 14 days and also the course start
-        past_datetime = datetime.utcnow().replace(tzinfo=pytz.UTC) - timedelta(days=20)
+        past_datetime = now() - timedelta(days=20)
         entitlement.created = past_datetime
         self.enrollment.created = past_datetime
         self.course.start = past_datetime
@@ -87,7 +87,7 @@ class TestModels(TestCase):
 
         assert entitlement.is_entitlement_refundable() is True
 
-        entitlement = CourseEntitlementFactory.create(expired_at=datetime.now())
+        entitlement = CourseEntitlementFactory.create(expired_at=now())
 
         assert entitlement.is_entitlement_refundable() is False
 
@@ -111,7 +111,7 @@ class TestModels(TestCase):
 
         # Create a date 20 days in the past (greater than the policy expire period of 14 days)
         # and apply it to both the entitlement and the course
-        past_datetime = datetime.utcnow().replace(tzinfo=pytz.UTC) - timedelta(days=20)
+        past_datetime = now() - timedelta(days=20)
         entitlement = CourseEntitlementFactory.create(enrollment_course_run=self.enrollment, created=past_datetime)
         self.enrollment.created = past_datetime
         self.course.start = past_datetime
@@ -121,7 +121,7 @@ class TestModels(TestCase):
 
         assert entitlement.is_entitlement_regainable() is False
 
-        entitlement = CourseEntitlementFactory.create(expired_at=datetime.now())
+        entitlement = CourseEntitlementFactory.create(expired_at=now())
 
         assert entitlement.is_entitlement_regainable
 
@@ -147,7 +147,7 @@ class TestModels(TestCase):
         assert entitlement.expired_at is None
 
         # Verify an entitlement from two years ago is expired and the db row is updated
-        past_datetime = datetime.utcnow().replace(tzinfo=pytz.UTC) - timedelta(days=365 * 2)
+        past_datetime = now() - timedelta(days=365 * 2)
         entitlement.created = past_datetime
         entitlement.save()
         expired_at_datetime = entitlement.expired_at_datetime
@@ -163,7 +163,7 @@ class TestModels(TestCase):
 
         # Verify that an entitlement that has been redeemed but not within 14 days
         # and the course started more than two weeks ago is expired
-        past_datetime = datetime.utcnow().replace(tzinfo=pytz.UTC) - timedelta(days=20)
+        past_datetime = now() - timedelta(days=20)
         entitlement.created = past_datetime
         self.enrollment.created = past_datetime
         self.course.start = past_datetime
@@ -178,8 +178,8 @@ class TestModels(TestCase):
         # Verify that an entitlement that has just been created, but the user has been enrolled in the course for
         # greater than 14 days, and the course started more than 14 days ago is not expired
         entitlement = CourseEntitlementFactory.create(enrollment_course_run=self.enrollment)
-        past_datetime = datetime.utcnow().replace(tzinfo=pytz.UTC) - timedelta(days=20)
-        entitlement.created = datetime.utcnow().replace(tzinfo=pytz.UTC)
+        past_datetime = now() - timedelta(days=20)
+        entitlement.created = now()
         self.enrollment.created = past_datetime
         self.course.start = past_datetime
         entitlement.save()
@@ -193,11 +193,11 @@ class TestModels(TestCase):
         # Verify a date 451 days in the past (1 days after the policy expiration)
         # That is enrolled and started in within the regain period is still expired
         entitlement = CourseEntitlementFactory.create(enrollment_course_run=self.enrollment)
-        expired_datetime = datetime.utcnow().replace(tzinfo=pytz.UTC) - timedelta(days=451)
+        expired_datetime = now() - timedelta(days=451)
         entitlement.created = expired_datetime
-        now = datetime.now(tz=pytz.UTC)
-        self.enrollment.created = now
-        self.course.start = now
+        start = now()
+        self.enrollment.created = start
+        self.course.start = start
         entitlement.save()
         self.course.save()
         self.enrollment.save()
diff --git a/common/djangoapps/student/tests/test_parental_controls.py b/common/djangoapps/student/tests/test_parental_controls.py
index 9382ea00d6..1b6a7c3816 100644
--- a/common/djangoapps/student/tests/test_parental_controls.py
+++ b/common/djangoapps/student/tests/test_parental_controls.py
@@ -4,6 +4,7 @@ import datetime
 
 from django.test import TestCase
 from django.test.utils import override_settings
+from django.utils.timezone import now
 
 from student.models import UserProfile
 from student.tests.factories import UserFactory
@@ -40,20 +41,20 @@ class ProfileParentalControlsTest(TestCase):
         self.assertFalse(self.profile.requires_parental_consent(default_requires_consent=False))
 
         # Verify that even a child does not require parental consent
-        current_year = datetime.datetime.now().year
+        current_year = now().year
         self.set_year_of_birth(current_year - 10)
         self.assertFalse(self.profile.requires_parental_consent())
 
     def test_adult_user(self):
         """Verify the behavior for an adult."""
-        current_year = datetime.datetime.now().year
+        current_year = now().year
         self.set_year_of_birth(current_year - 20)
         self.assertFalse(self.profile.requires_parental_consent())
         self.assertTrue(self.profile.requires_parental_consent(age_limit=21))
 
     def test_child_user(self):
         """Verify the behavior for a child."""
-        current_year = datetime.datetime.now().year
+        current_year = now().year
 
         # Verify for a child born 13 years agp
         self.set_year_of_birth(current_year - 13)
@@ -70,14 +71,14 @@ class ProfileParentalControlsTest(TestCase):
         """Verify that a profile's image obeys parental controls."""
 
         # Verify that an image cannot be set for a user with no year of birth set
-        self.profile.profile_image_uploaded_at = datetime.datetime.now()
+        self.profile.profile_image_uploaded_at = now()
         self.profile.save()
         self.assertFalse(self.profile.has_profile_image)
 
         # Verify that an image can be set for an adult user
-        current_year = datetime.datetime.now().year
+        current_year = now().year
         self.set_year_of_birth(current_year - 20)
-        self.profile.profile_image_uploaded_at = datetime.datetime.now()
+        self.profile.profile_image_uploaded_at = now()
         self.profile.save()
         self.assertTrue(self.profile.has_profile_image)
 
diff --git a/common/djangoapps/student/tests/test_recent_enrollments.py b/common/djangoapps/student/tests/test_recent_enrollments.py
index 21fe3339b6..542f484be1 100644
--- a/common/djangoapps/student/tests/test_recent_enrollments.py
+++ b/common/djangoapps/student/tests/test_recent_enrollments.py
@@ -7,6 +7,7 @@ import unittest
 import ddt
 from django.conf import settings
 from django.core.urlresolvers import reverse
+from django.utils.timezone import now
 from nose.plugins.attrib import attr
 from opaque_keys.edx import locator
 from pytz import UTC
@@ -43,7 +44,7 @@ class TestRecentEnrollments(ModuleStoreTestCase, XssTestMixin):
         # Old Course
         old_course_location = locator.CourseLocator('Org0', 'Course0', 'Run0')
         __, enrollment = self._create_course_and_enrollment(old_course_location)
-        enrollment.created = datetime.datetime(1900, 12, 31, 0, 0, 0, 0)
+        enrollment.created = datetime.datetime(1900, 12, 31, 0, 0, 0, 0, tzinfo=UTC)
         enrollment.save()
 
         # New Course
@@ -107,7 +108,7 @@ class TestRecentEnrollments(ModuleStoreTestCase, XssTestMixin):
                 'Run{num}'.format(num=idx)
             )
             course, enrollment = self._create_course_and_enrollment(course_location)
-            enrollment.created = datetime.datetime.now(UTC) - datetime.timedelta(seconds=seconds_past)
+            enrollment.created = now() - datetime.timedelta(seconds=seconds_past)
             enrollment.save()
             courses.append(course)
 
diff --git a/common/djangoapps/student/tests/test_views.py b/common/djangoapps/student/tests/test_views.py
index 38b96578f8..51b029b73b 100644
--- a/common/djangoapps/student/tests/test_views.py
+++ b/common/djangoapps/student/tests/test_views.py
@@ -1,17 +1,17 @@
 """
 Test the student dashboard view.
 """
-import datetime
 import itertools
 import json
 import unittest
+from datetime import timedelta
 
 import ddt
-import pytz
 from django.conf import settings
 from django.core.urlresolvers import reverse
 from django.test import RequestFactory, TestCase
 from django.test.utils import override_settings
+from django.utils.timezone import now
 from edx_oauth2_provider.constants import AUTHORIZED_CLIENTS_SESSION_KEY
 from edx_oauth2_provider.tests.factories import ClientFactory, TrustedClientFactory
 from milestones.tests.utils import MilestonesTestCaseMixin
@@ -241,9 +241,9 @@ class StudentDashboardTests(SharedModuleStoreTestCase, MilestonesTestCaseMixin):
 
     EMAIL_SETTINGS_ELEMENT_ID = "#actions-item-email-settings-0"
     ENABLED_SIGNALS = ['course_published']
-    TOMORROW = datetime.datetime.now(pytz.utc) + datetime.timedelta(days=1)
-    THREE_YEARS_FROM_NOW = datetime.datetime.now(pytz.utc) + datetime.timedelta(days=(365 * 3))
-    THREE_YEARS_AGO = datetime.datetime.now(pytz.utc) - datetime.timedelta(days=(365 * 3))
+    TOMORROW = now() + timedelta(days=1)
+    THREE_YEARS_FROM_NOW = now() + timedelta(days=(365 * 3))
+    THREE_YEARS_AGO = now() - timedelta(days=(365 * 3))
     MOCK_SETTINGS = {
         'FEATURES': {
             'DISABLE_START_DATES': False,
@@ -391,7 +391,7 @@ class StudentDashboardTests(SharedModuleStoreTestCase, MilestonesTestCaseMixin):
         CourseEntitlementFactory(
             user=self.user,
             created=self.THREE_YEARS_AGO,
-            expired_at=datetime.datetime.now()
+            expired_at=now()
         )
         mock_course_overview.return_value = CourseOverviewFactory(start=self.TOMORROW)
         mock_course_runs.return_value = [
diff --git a/common/djangoapps/third_party_auth/tasks.py b/common/djangoapps/third_party_auth/tasks.py
index b53e7f9850..185f4974fa 100644
--- a/common/djangoapps/third_party_auth/tasks.py
+++ b/common/djangoapps/third_party_auth/tasks.py
@@ -10,6 +10,7 @@ import dateutil.parser
 import pytz
 import requests
 from celery.task import task
+from django.utils.timezone import now
 from lxml import etree
 from onelogin.saml2.utils import OneLogin_Saml2_Utils
 from requests import exceptions
@@ -188,7 +189,7 @@ def _update_data(entity_id, public_key, sso_url, expires_at):
         True if a new record was created. (Either this is a new provider or something changed.)
     """
     data_obj = SAMLProviderData.current(entity_id)
-    fetched_at = datetime.datetime.now()
+    fetched_at = now()
     if data_obj and (data_obj.public_key == public_key and data_obj.sso_url == sso_url):
         data_obj.expires_at = expires_at
         data_obj.fetched_at = fetched_at
diff --git a/lms/djangoapps/grades/tests/test_models.py b/lms/djangoapps/grades/tests/test_models.py
index 18b4d4f062..dd904addc0 100644
--- a/lms/djangoapps/grades/tests/test_models.py
+++ b/lms/djangoapps/grades/tests/test_models.py
@@ -205,7 +205,7 @@ class PersistentSubsectionGradeTest(GradesModelTestCase):
             "user_id": 12345,
             "usage_key": self.usage_key,
             "course_version": "deadbeef",
-            "subtree_edited_timestamp": "2016-08-01 18:53:24.354741",
+            "subtree_edited_timestamp": "2016-08-01 18:53:24.354741Z",
             "earned_all": 6.0,
             "possible_all": 12.0,
             "earned_graded": 6.0,
@@ -338,6 +338,7 @@ class PersistentCourseGradesTest(GradesModelTestCase):
                 minute=53,
                 second=24,
                 microsecond=354741,
+                tzinfo=pytz.UTC,
             ),
             "percent_grade": 77.7,
             "letter_grade": "Great job",
diff --git a/lms/djangoapps/grades/tests/utils.py b/lms/djangoapps/grades/tests/utils.py
index 4842826700..721b65cfe3 100644
--- a/lms/djangoapps/grades/tests/utils.py
+++ b/lms/djangoapps/grades/tests/utils.py
@@ -4,6 +4,7 @@ Utilities for grades related tests
 from contextlib import contextmanager
 from datetime import datetime
 
+import pytz
 from mock import patch, MagicMock
 
 from courseware.model_data import FieldDataCache
@@ -30,7 +31,7 @@ def mock_passing_grade(letter_grade='Pass', percent=0.75, ):
 
 
 @contextmanager
-def mock_get_score(earned=0, possible=1, first_attempted=datetime(2000, 1, 1, 0, 0, 0)):
+def mock_get_score(earned=0, possible=1, first_attempted=datetime(2000, 1, 1, 0, 0, 0, tzinfo=pytz.UTC)):
     """
     Mocks the get_score function to return a valid grade.
     """
@@ -48,7 +49,7 @@ def mock_get_score(earned=0, possible=1, first_attempted=datetime(2000, 1, 1, 0,
 
 
 @contextmanager
-def mock_get_submissions_score(earned=0, possible=1, first_attempted=datetime(2000, 1, 1, 0, 0, 0)):
+def mock_get_submissions_score(earned=0, possible=1, first_attempted=datetime(2000, 1, 1, 0, 0, 0, tzinfo=pytz.UTC)):
     """
     Mocks the _get_submissions_score function to return the specified values
     """
diff --git a/lms/djangoapps/instructor_task/management/commands/tests/test_fail_old_tasks.py b/lms/djangoapps/instructor_task/management/commands/tests/test_fail_old_tasks.py
index 70eb50175f..dfa3f89f44 100644
--- a/lms/djangoapps/instructor_task/management/commands/tests/test_fail_old_tasks.py
+++ b/lms/djangoapps/instructor_task/management/commands/tests/test_fail_old_tasks.py
@@ -1,6 +1,7 @@
 from datetime import datetime
 
 import ddt
+import pytz
 from celery.states import FAILURE
 from django.core.management import call_command
 from django.core.management.base import CommandError
@@ -45,7 +46,7 @@ class TestFailOldQueueingTasksCommand(InstructorTaskTestCase):
         Override each task's "created" date
         """
         for task in self.tasks:
-            task.created = datetime.strptime(created_date, "%Y-%m-%d")
+            task.created = datetime.strptime(created_date, "%Y-%m-%d").replace(tzinfo=pytz.UTC)
             task.save()
 
     def get_tasks(self):
diff --git a/lms/djangoapps/support/tests/test_refund.py b/lms/djangoapps/support/tests/test_refund.py
index 6008ed1170..dfe5508b7e 100644
--- a/lms/djangoapps/support/tests/test_refund.py
+++ b/lms/djangoapps/support/tests/test_refund.py
@@ -67,7 +67,7 @@ class RefundTests(ModuleStoreTestCase):
             self.order = Order.get_cart_for_user(self.student)
             CertificateItem.add_to_order(self.order, self.course_id, 1, self.course_mode.mode_slug)
             self.order.purchase()
-        self.course_mode.expiration_datetime = datetime.datetime(1983, 4, 6)
+        self.course_mode.expiration_datetime = datetime.datetime(1983, 4, 6, tzinfo=pytz.UTC)
         self.course_mode.save()
 
     def test_support_access(self):
@@ -96,7 +96,7 @@ class RefundTests(ModuleStoreTestCase):
     @patch('student.models.CourseEnrollment.refund_cutoff_date')
     def test_not_refundable(self, cutoff_date):
         self._enroll()
-        self.course_mode.expiration_datetime = datetime.datetime(2033, 4, 6)
+        self.course_mode.expiration_datetime = datetime.datetime(2033, 4, 6, tzinfo=pytz.UTC)
         self.course_mode.save()
         cutoff_date.return_value = datetime.datetime.now(pytz.UTC) + datetime.timedelta(days=1)
         response = self.client.post('/support/refund/', self.form_pars)
diff --git a/openedx/core/lib/api/tests/test_authentication.py b/openedx/core/lib/api/tests/test_authentication.py
index b4d91469ee..6a28112814 100644
--- a/openedx/core/lib/api/tests/test_authentication.py
+++ b/openedx/core/lib/api/tests/test_authentication.py
@@ -9,7 +9,7 @@ import itertools
 import json
 import unittest
 from collections import namedtuple
-from datetime import datetime, timedelta
+from datetime import timedelta
 
 import ddt
 import pytest
@@ -20,6 +20,7 @@ from django.http import HttpResponse
 from django.test import TestCase
 from django.test.utils import override_settings
 from django.utils.http import urlencode
+from django.utils.timezone import now
 from nose.plugins.attrib import attr
 from oauth2_provider import models as dot_models
 from rest_framework import status
@@ -123,7 +124,7 @@ class OAuth2Tests(TestCase):
             user=self.user,
             token='dot-access-token',
             application=self.dot_oauth2_client,
-            expires=datetime.now() + timedelta(days=30),
+            expires=now() + timedelta(days=30),
         )
 
         # This is the a change we've made from the django-rest-framework-oauth version
@@ -253,7 +254,7 @@ class OAuth2Tests(TestCase):
     @unittest.skipUnless(oauth2_provider, 'django-oauth2-provider not installed')
     def test_post_form_with_expired_access_token_failing_auth(self):
         """Ensure POSTing with expired access token fails with a 'token_expired' error"""
-        self.access_token.expires = datetime.now() - timedelta(seconds=10)  # 10 seconds late
+        self.access_token.expires = now() - timedelta(seconds=10)  # 10 seconds late
         self.access_token.save()
         response = self.post_with_bearer_token('/oauth2-test/')
         self.check_error_codes(