diff --git a/chrono/agendas/management/commands/anonymize_bookings.py b/chrono/agendas/management/commands/anonymize_bookings.py
index e4540e87..0e4ba188 100644
--- a/chrono/agendas/management/commands/anonymize_bookings.py
+++ b/chrono/agendas/management/commands/anonymize_bookings.py
@@ -18,9 +18,9 @@ from datetime import timedelta
 
 from django.core.management.base import BaseCommand
 from django.db.models import F
-from django.utils import timezone
 
 from chrono.agendas.models import Booking
+from chrono.utils import timezone
 
 
 class Command(BaseCommand):
diff --git a/chrono/agendas/management/commands/cancel_events.py b/chrono/agendas/management/commands/cancel_events.py
index 37ff4af8..880fba4f 100644
--- a/chrono/agendas/management/commands/cancel_events.py
+++ b/chrono/agendas/management/commands/cancel_events.py
@@ -18,10 +18,10 @@ from datetime import timedelta
 
 from django.core.management.base import BaseCommand
 from django.db import transaction
-from django.utils import timezone
 from requests import RequestException
 
 from chrono.agendas.models import Event, EventCancellationReport
+from chrono.utils import timezone
 
 
 class Command(BaseCommand):
diff --git a/chrono/agendas/management/commands/send_booking_reminders.py b/chrono/agendas/management/commands/send_booking_reminders.py
index cf9c22b7..0fa44826 100644
--- a/chrono/agendas/management/commands/send_booking_reminders.py
+++ b/chrono/agendas/management/commands/send_booking_reminders.py
@@ -20,9 +20,10 @@ import pytz
 from django.conf import settings
 from django.core.management.base import BaseCommand
 from django.db.models import F
-from django.utils import timezone, translation
+from django.utils import translation
 
 from chrono.agendas.models import Booking
+from chrono.utils import timezone
 
 from .utils import send_reminder
 
diff --git a/chrono/agendas/management/commands/send_email_notifications.py b/chrono/agendas/management/commands/send_email_notifications.py
index f1f8f559..ba39074d 100644
--- a/chrono/agendas/management/commands/send_email_notifications.py
+++ b/chrono/agendas/management/commands/send_email_notifications.py
@@ -22,10 +22,11 @@ from django.core.mail import send_mail
 from django.core.management.base import BaseCommand
 from django.db.transaction import atomic
 from django.template.loader import render_to_string
-from django.utils import timezone, translation
+from django.utils import translation
 from django.utils.translation import gettext_lazy as _
 
 from chrono.agendas.models import Agenda
+from chrono.utils import timezone
 
 
 class Command(BaseCommand):
diff --git a/chrono/agendas/management/commands/utils.py b/chrono/agendas/management/commands/utils.py
index edec8362..27c8c974 100644
--- a/chrono/agendas/management/commands/utils.py
+++ b/chrono/agendas/management/commands/utils.py
@@ -5,10 +5,10 @@ from django.core.mail import send_mail
 from django.db.transaction import atomic
 from django.template import Context, Template, TemplateSyntaxError, VariableDoesNotExist
 from django.template.loader import render_to_string
-from django.utils import timezone
 from django.utils.translation import gettext_lazy as _
 from requests import RequestException
 
+from chrono.utils import timezone
 from chrono.utils.requests_wrapper import requests
 
 
diff --git a/chrono/agendas/migrations/0006_auto_20160707_1357.py b/chrono/agendas/migrations/0006_auto_20160707_1357.py
index 7ae48771..2de368c3 100644
--- a/chrono/agendas/migrations/0006_auto_20160707_1357.py
+++ b/chrono/agendas/migrations/0006_auto_20160707_1357.py
@@ -1,7 +1,8 @@
 import datetime
 
 from django.db import migrations, models
-from django.utils.timezone import utc
+
+from chrono.utils.timezone import utc
 
 
 class Migration(migrations.Migration):
diff --git a/chrono/agendas/migrations/0020_auto_20171102_1021.py b/chrono/agendas/migrations/0020_auto_20171102_1021.py
index 6686bd2f..bc56bff9 100644
--- a/chrono/agendas/migrations/0020_auto_20171102_1021.py
+++ b/chrono/agendas/migrations/0020_auto_20171102_1021.py
@@ -1,7 +1,8 @@
 import datetime
 
 from django.db import migrations, models
-from django.utils.timezone import utc
+
+from chrono.utils.timezone import utc
 
 
 class Migration(migrations.Migration):
diff --git a/chrono/agendas/migrations/0102_publication_datetime.py b/chrono/agendas/migrations/0102_publication_datetime.py
index 6b560a46..2f79d86b 100644
--- a/chrono/agendas/migrations/0102_publication_datetime.py
+++ b/chrono/agendas/migrations/0102_publication_datetime.py
@@ -1,7 +1,8 @@
 import datetime
 
 from django.db import migrations
-from django.utils.timezone import localtime, make_aware
+
+from chrono.utils.timezone import localtime, make_aware
 
 
 def forwards(apps, schema_editor):
diff --git a/chrono/agendas/migrations/0138_sharedcustodyagenda_date_start.py b/chrono/agendas/migrations/0138_sharedcustodyagenda_date_start.py
index 29bb4625..371c346a 100644
--- a/chrono/agendas/migrations/0138_sharedcustodyagenda_date_start.py
+++ b/chrono/agendas/migrations/0138_sharedcustodyagenda_date_start.py
@@ -1,8 +1,9 @@
 # Generated by Django 2.2.26 on 2022-06-29 13:14
 
-import django.utils.timezone
 from django.db import migrations, models
 
+import chrono.utils.timezone
+
 
 class Migration(migrations.Migration):
 
@@ -14,7 +15,7 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='sharedcustodyagenda',
             name='date_start',
-            field=models.DateTimeField(default=django.utils.timezone.now, verbose_name='Start'),
+            field=models.DateTimeField(default=chrono.utils.timezone.now, verbose_name='Start'),
             preserve_default=False,
         ),
     ]
diff --git a/chrono/agendas/models.py b/chrono/agendas/models.py
index 6e100285..6ad8690f 100644
--- a/chrono/agendas/models.py
+++ b/chrono/agendas/models.py
@@ -63,7 +63,6 @@ from django.utils.html import escape
 from django.utils.module_loading import import_string
 from django.utils.safestring import mark_safe
 from django.utils.text import slugify
-from django.utils.timezone import is_aware, localtime, make_aware, make_naive, now, utc
 from django.utils.translation import gettext
 from django.utils.translation import gettext_lazy as _
 from django.utils.translation import ngettext, pgettext_lazy
@@ -74,6 +73,7 @@ from chrono.utils.db import ArraySubquery, SumCardinality
 from chrono.utils.misc import AgendaImportError, ICSError, clean_import_data, generate_slug
 from chrono.utils.publik_urls import translate_from_publik_url
 from chrono.utils.requests_wrapper import requests as requests_wrapper
+from chrono.utils.timezone import is_aware, localtime, make_aware, make_naive, now, utc
 
 AGENDA_KINDS = (
     ('events', _('Events')),
@@ -2973,7 +2973,7 @@ class TimePeriodException(models.Model):
         def import_datetime(s):
             '''Import datetime as a naive ISO8601 serialization'''
             try:
-                return make_aware(datetime.datetime.strptime(s, '%Y-%m-%d %H:%M:%S'), is_dst=True)
+                return make_aware(datetime.datetime.strptime(s, '%Y-%m-%d %H:%M:%S'))
             except ValueError:
                 raise AgendaImportError(_('Bad datetime format "%s"') % s)
 
diff --git a/chrono/api/views.py b/chrono/api/views.py
index 4a8b0f79..7ae8a818 100644
--- a/chrono/api/views.py
+++ b/chrono/api/views.py
@@ -32,7 +32,6 @@ from django.urls import reverse
 from django.utils.dates import WEEKDAYS
 from django.utils.encoding import force_str
 from django.utils.formats import date_format
-from django.utils.timezone import localtime, make_aware, now
 from django.utils.translation import gettext
 from django.utils.translation import gettext_lazy as _
 from django.utils.translation import gettext_noop as N_
@@ -58,6 +57,7 @@ from chrono.api import serializers
 from chrono.api.utils import APIError, APIErrorBadRequest, Response
 from chrono.interval import IntervalSet
 from chrono.utils.publik_urls import translate_to_publik_url
+from chrono.utils.timezone import localtime, make_aware, now
 
 
 def format_response_datetime(dt):
diff --git a/chrono/manager/forms.py b/chrono/manager/forms.py
index b1fce2aa..4192dea3 100644
--- a/chrono/manager/forms.py
+++ b/chrono/manager/forms.py
@@ -37,7 +37,6 @@ from django.template import Context, Template, TemplateSyntaxError, VariableDoes
 from django.utils.encoding import force_str
 from django.utils.formats import date_format
 from django.utils.html import format_html, mark_safe
-from django.utils.timezone import localtime, make_aware, now
 from django.utils.translation import gettext_lazy as _
 
 from chrono.agendas.models import (
@@ -68,6 +67,7 @@ from chrono.agendas.models import (
     generate_slug,
 )
 from chrono.utils.lingo import get_agenda_check_types
+from chrono.utils.timezone import localtime, make_aware, now
 
 from . import widgets
 from .widgets import SplitDateTimeField, WeekdaysWidget
diff --git a/chrono/manager/views.py b/chrono/manager/views.py
index 7a548a45..0411c90a 100644
--- a/chrono/manager/views.py
+++ b/chrono/manager/views.py
@@ -42,7 +42,6 @@ from django.utils.dates import MONTHS
 from django.utils.encoding import force_str
 from django.utils.formats import date_format
 from django.utils.html import format_html
-from django.utils.timezone import localtime, make_aware, make_naive, now
 from django.utils.translation import gettext_lazy as _
 from django.utils.translation import ngettext
 from django.views.generic import (
@@ -88,6 +87,7 @@ from chrono.agendas.models import (
     VirtualMember,
 )
 from chrono.utils.date import get_weekday_index
+from chrono.utils.timezone import localtime, make_aware, make_naive, now
 
 from .forms import (
     AgendaAddForm,
diff --git a/chrono/utils/timezone.py b/chrono/utils/timezone.py
new file mode 100644
index 00000000..74dfa9d2
--- /dev/null
+++ b/chrono/utils/timezone.py
@@ -0,0 +1,66 @@
+# chrono - agendas system
+# Copyright (C) 2023  Entr'ouvert
+#
+# This program is free software: you can redistribute it and/or modify it
+# under the terms of the GNU Affero General Public License as published
+# by the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import datetime
+import functools
+import zoneinfo
+
+import django.utils.timezone
+from django.conf import settings
+
+utc = zoneinfo.ZoneInfo('UTC')
+
+
+@functools.lru_cache()
+def get_default_timezone():
+    """
+    Return the default time zone as a tzinfo instance.
+
+    This is the time zone defined by settings.TIME_ZONE.
+    """
+    return zoneinfo.ZoneInfo(settings.TIME_ZONE)
+
+
+def localtime(value=None, timezone=None):
+    if timezone is None:
+        timezone = get_default_timezone()
+    return django.utils.timezone.localtime(value=value, timezone=timezone)
+
+
+is_aware = django.utils.timezone.is_aware
+
+
+def make_aware(value, timezone=None, is_dst=None):
+    if timezone is None:
+        timezone = get_default_timezone()
+    return django.utils.timezone.make_aware(value, timezone=timezone, is_dst=is_dst)
+
+
+def make_naive(value, timezone=None):
+    if timezone is None:
+        timezone = get_default_timezone()
+    return django.utils.timezone.make_naive(value, timezone=timezone)
+
+
+def now():
+    """
+    Return an aware or naive datetime.datetime, depending on settings.USE_TZ.
+    """
+    if settings.USE_TZ:
+        # timeit shows that datetime.now(tz=utc) is 24% slower
+        return datetime.datetime.utcnow().replace(tzinfo=utc)
+    else:
+        return datetime.datetime.now()
diff --git a/tests/api/conftest.py b/tests/api/conftest.py
index 06109231..a6631644 100644
--- a/tests/api/conftest.py
+++ b/tests/api/conftest.py
@@ -2,9 +2,9 @@ import datetime
 
 import pytest
 from django.contrib.auth import get_user_model
-from django.utils.timezone import localtime, make_aware, now
 
 from chrono.agendas.models import Agenda, Desk, Event, MeetingType, TimePeriod, VirtualMember
+from chrono.utils.timezone import localtime, make_aware, now
 
 User = get_user_model()
 
diff --git a/tests/api/datetimes/test_all.py b/tests/api/datetimes/test_all.py
index 6c9a1039..72b71aee 100644
--- a/tests/api/datetimes/test_all.py
+++ b/tests/api/datetimes/test_all.py
@@ -5,9 +5,9 @@ import pytest
 from django.db import connection
 from django.test import override_settings
 from django.test.utils import CaptureQueriesContext
-from django.utils.timezone import localtime, make_aware, make_naive, now
 
 from chrono.agendas.models import Agenda, Booking, Desk, Event, EventsType, TimePeriodException
+from chrono.utils.timezone import localtime, make_aware, make_naive, now
 from tests.utils import login
 
 pytestmark = pytest.mark.django_db
diff --git a/tests/api/datetimes/test_events_multiple_agendas.py b/tests/api/datetimes/test_events_multiple_agendas.py
index c351f6c8..43d4a2c7 100644
--- a/tests/api/datetimes/test_events_multiple_agendas.py
+++ b/tests/api/datetimes/test_events_multiple_agendas.py
@@ -3,7 +3,6 @@ import datetime
 import pytest
 from django.db import connection
 from django.test.utils import CaptureQueriesContext
-from django.utils.timezone import localtime, make_aware, now
 
 from chrono.agendas.models import (
     Agenda,
@@ -22,6 +21,7 @@ from chrono.agendas.models import (
     TimePeriodExceptionGroup,
     UnavailabilityCalendar,
 )
+from chrono.utils.timezone import localtime, make_aware, now
 
 pytestmark = pytest.mark.django_db
 
diff --git a/tests/api/datetimes/test_meetings.py b/tests/api/datetimes/test_meetings.py
index 3b35a288..6f953d76 100644
--- a/tests/api/datetimes/test_meetings.py
+++ b/tests/api/datetimes/test_meetings.py
@@ -3,7 +3,6 @@ import datetime
 import pytest
 from django.db import connection
 from django.test.utils import CaptureQueriesContext
-from django.utils.timezone import localtime, make_aware, now
 
 from chrono.agendas.models import (
     Agenda,
@@ -17,6 +16,7 @@ from chrono.agendas.models import (
     UnavailabilityCalendar,
     VirtualMember,
 )
+from chrono.utils.timezone import localtime, make_aware, now
 
 pytestmark = pytest.mark.django_db
 
diff --git a/tests/api/datetimes/test_recurring_events.py b/tests/api/datetimes/test_recurring_events.py
index 78b5a7c6..7ea8a660 100644
--- a/tests/api/datetimes/test_recurring_events.py
+++ b/tests/api/datetimes/test_recurring_events.py
@@ -3,7 +3,6 @@ import datetime
 import pytest
 from django.db import connection
 from django.test.utils import CaptureQueriesContext
-from django.utils.timezone import make_aware, now
 
 from chrono.agendas.models import (
     Agenda,
@@ -22,6 +21,7 @@ from chrono.agendas.models import (
     TimePeriodExceptionGroup,
     UnavailabilityCalendar,
 )
+from chrono.utils.timezone import make_aware, now
 
 pytestmark = pytest.mark.django_db
 
diff --git a/tests/api/fillslot/test_all.py b/tests/api/fillslot/test_all.py
index c750f7ba..b16a9eb4 100644
--- a/tests/api/fillslot/test_all.py
+++ b/tests/api/fillslot/test_all.py
@@ -6,7 +6,6 @@ from unittest import mock
 import pytest
 from django.db import IntegrityError, connection
 from django.test.utils import CaptureQueriesContext
-from django.utils.timezone import localtime, now
 
 from chrono.agendas.models import (
     Agenda,
@@ -19,6 +18,7 @@ from chrono.agendas.models import (
     TimePeriod,
     VirtualMember,
 )
+from chrono.utils.timezone import localtime, now
 
 pytestmark = pytest.mark.django_db
 
diff --git a/tests/api/fillslot/test_events.py b/tests/api/fillslot/test_events.py
index 1aa770bf..5b4a9624 100644
--- a/tests/api/fillslot/test_events.py
+++ b/tests/api/fillslot/test_events.py
@@ -3,9 +3,9 @@ import datetime
 import pytest
 from django.db import connection
 from django.test.utils import CaptureQueriesContext
-from django.utils.timezone import localtime, now
 
 from chrono.agendas.models import Agenda, Booking, Event, EventsType
+from chrono.utils.timezone import localtime, now
 
 pytestmark = pytest.mark.django_db
 
diff --git a/tests/api/fillslot/test_events_multiple_agendas.py b/tests/api/fillslot/test_events_multiple_agendas.py
index a2daf1ac..04e5d173 100644
--- a/tests/api/fillslot/test_events_multiple_agendas.py
+++ b/tests/api/fillslot/test_events_multiple_agendas.py
@@ -3,7 +3,6 @@ import datetime
 import pytest
 from django.db import connection
 from django.test.utils import CaptureQueriesContext
-from django.utils.timezone import localtime, make_aware, now
 
 from chrono.agendas.models import (
     Agenda,
@@ -17,6 +16,7 @@ from chrono.agendas.models import (
     SharedCustodyRule,
     Subscription,
 )
+from chrono.utils.timezone import localtime, make_aware, now
 
 pytestmark = pytest.mark.django_db
 
diff --git a/tests/api/fillslot/test_recurring_events.py b/tests/api/fillslot/test_recurring_events.py
index 74612d86..dd67f3f7 100644
--- a/tests/api/fillslot/test_recurring_events.py
+++ b/tests/api/fillslot/test_recurring_events.py
@@ -3,7 +3,6 @@ import datetime
 import pytest
 from django.db import connection
 from django.test.utils import CaptureQueriesContext
-from django.utils.timezone import now
 
 from chrono.agendas.models import (
     Agenda,
@@ -17,6 +16,7 @@ from chrono.agendas.models import (
     SharedCustodyRule,
     Subscription,
 )
+from chrono.utils.timezone import now
 
 pytestmark = pytest.mark.django_db
 
diff --git a/tests/api/test_agenda.py b/tests/api/test_agenda.py
index eb5381bb..e0fd3577 100644
--- a/tests/api/test_agenda.py
+++ b/tests/api/test_agenda.py
@@ -4,7 +4,6 @@ import pytest
 from django.contrib.auth.models import Group
 from django.db import connection
 from django.test.utils import CaptureQueriesContext
-from django.utils.timezone import localtime, now
 
 from chrono.agendas.models import (
     Agenda,
@@ -16,6 +15,7 @@ from chrono.agendas.models import (
     Resource,
     TimePeriodException,
 )
+from chrono.utils.timezone import localtime, now
 
 pytestmark = pytest.mark.django_db
 
diff --git a/tests/api/test_booking.py b/tests/api/test_booking.py
index 41bdf73b..bc2b1d53 100644
--- a/tests/api/test_booking.py
+++ b/tests/api/test_booking.py
@@ -4,10 +4,10 @@ from unittest import mock
 import pytest
 from django.db import connection
 from django.test.utils import CaptureQueriesContext
-from django.utils.timezone import localtime, make_aware, now
 
 from chrono.agendas.models import Agenda, Booking, BookingColor, Category, Desk, Event, MeetingType
 from chrono.utils.lingo import CheckType
+from chrono.utils.timezone import localtime, make_aware, now
 
 pytestmark = pytest.mark.django_db
 
diff --git a/tests/api/test_event.py b/tests/api/test_event.py
index a5b7b002..3c3aad3e 100644
--- a/tests/api/test_event.py
+++ b/tests/api/test_event.py
@@ -3,9 +3,9 @@ import datetime
 import pytest
 from django.db import connection
 from django.test.utils import CaptureQueriesContext
-from django.utils.timezone import localtime, make_aware, now
 
 from chrono.agendas.models import Agenda, Booking, Event, EventsType, Subscription
+from chrono.utils.timezone import localtime, make_aware, now
 
 pytestmark = pytest.mark.django_db
 
diff --git a/tests/api/test_serializer.py b/tests/api/test_serializer.py
index d5f927bc..4771caae 100644
--- a/tests/api/test_serializer.py
+++ b/tests/api/test_serializer.py
@@ -1,10 +1,10 @@
 import datetime
 
 import pytest
-from django.utils.timezone import now
 
 from chrono.agendas.models import Agenda, Subscription
 from chrono.api.serializers import AgendaOrSubscribedSlugsSerializer
+from chrono.utils.timezone import now
 
 pytestmark = pytest.mark.django_db
 
diff --git a/tests/api/test_shared_custody.py b/tests/api/test_shared_custody.py
index f2061d7a..2802b901 100644
--- a/tests/api/test_shared_custody.py
+++ b/tests/api/test_shared_custody.py
@@ -2,9 +2,9 @@ import datetime
 
 import pytest
 from django.core.files.base import ContentFile
-from django.utils.timezone import now
 
 from chrono.agendas.models import Person, SharedCustodyAgenda, SharedCustodySettings, UnavailabilityCalendar
+from chrono.utils.timezone import now
 
 pytestmark = pytest.mark.django_db
 
diff --git a/tests/api/test_statistics.py b/tests/api/test_statistics.py
index 639a0d1a..529885f9 100644
--- a/tests/api/test_statistics.py
+++ b/tests/api/test_statistics.py
@@ -1,7 +1,7 @@
 import pytest
-from django.utils.timezone import now
 
 from chrono.agendas.models import Agenda, Booking, Category, Event
+from chrono.utils.timezone import now
 
 pytestmark = pytest.mark.django_db
 
diff --git a/tests/api/test_subscription.py b/tests/api/test_subscription.py
index 5e11a332..3745d0ca 100644
--- a/tests/api/test_subscription.py
+++ b/tests/api/test_subscription.py
@@ -1,9 +1,9 @@
 import datetime
 
 import pytest
-from django.utils.timezone import make_aware, now
 
 from chrono.agendas.models import Agenda, Booking, Event, Subscription
+from chrono.utils.timezone import make_aware, now
 
 pytestmark = pytest.mark.django_db
 
diff --git a/tests/manager/test_all.py b/tests/manager/test_all.py
index 636808ed..b0b15427 100644
--- a/tests/manager/test_all.py
+++ b/tests/manager/test_all.py
@@ -10,7 +10,6 @@ from django.core.management import call_command
 from django.db import connection
 from django.test import override_settings
 from django.test.utils import CaptureQueriesContext
-from django.utils.timezone import localtime, make_aware, now
 
 from chrono.agendas.models import (
     Agenda,
@@ -26,6 +25,7 @@ from chrono.agendas.models import (
     VirtualMember,
 )
 from chrono.utils.signature import check_query
+from chrono.utils.timezone import localtime, make_aware, now
 from tests.utils import login
 
 pytestmark = pytest.mark.django_db
@@ -1311,7 +1311,7 @@ def test_agenda_events_week_view(app, admin_user):
     assert len(resp.pyquery.find('.event-title')) == 2
 
     time = localtime(event.start_datetime).strftime('%H%M')
-    resp = resp.click('Dec. 9, 2020, 1 a.m.', index=1)
+    resp = resp.click('Dec. 9, 2020, 2 a.m.', index=1)
     resp = resp.click('Options')
     resp.form['start_datetime_1'] = '13:12'
     resp = resp.form.submit(status=302).follow()
@@ -1412,7 +1412,7 @@ def test_agenda_events_month_view(app, admin_user):
     assert len(resp.pyquery.find('.event-title')) == 10
 
     time = localtime(event.start_datetime).strftime('%H%M')
-    resp = resp.click('Dec. 9, 2020, 1 a.m.', index=1)
+    resp = resp.click('Dec. 9, 2020, 2 a.m.', index=1)
     resp = resp.click('Options')
     resp.form['start_datetime_1'] = '13:12'
     resp = resp.form.submit(status=302).follow()
diff --git a/tests/manager/test_event.py b/tests/manager/test_event.py
index 8b48d005..eaf998b6 100644
--- a/tests/manager/test_event.py
+++ b/tests/manager/test_event.py
@@ -8,11 +8,11 @@ from django.core.management import call_command
 from django.db import connection
 from django.test import override_settings
 from django.test.utils import CaptureQueriesContext
-from django.utils.timezone import localtime, make_aware, now
 from webtest import Upload
 
 from chrono.agendas.models import Agenda, Booking, Desk, Event, EventsType, Subscription
 from chrono.utils.lingo import CheckType
+from chrono.utils.timezone import localtime, make_aware, now
 from tests.utils import login
 
 pytestmark = pytest.mark.django_db
diff --git a/tests/manager/test_event_timesheet.py b/tests/manager/test_event_timesheet.py
index c7c913ff..4426a81a 100644
--- a/tests/manager/test_event_timesheet.py
+++ b/tests/manager/test_event_timesheet.py
@@ -4,9 +4,9 @@ import itertools
 import pytest
 from django.db import connection
 from django.test.utils import CaptureQueriesContext
-from django.utils.timezone import make_aware, now
 
 from chrono.agendas.models import Agenda, Booking, Event, Subscription
+from chrono.utils.timezone import make_aware, now
 from tests.utils import login
 
 pytestmark = pytest.mark.django_db
diff --git a/tests/manager/test_exception.py b/tests/manager/test_exception.py
index e4e0f8c0..7fb30e9f 100644
--- a/tests/manager/test_exception.py
+++ b/tests/manager/test_exception.py
@@ -10,7 +10,6 @@ from django.db import connection
 from django.test import override_settings
 from django.test.utils import CaptureQueriesContext
 from django.urls import reverse
-from django.utils.timezone import localtime, make_aware, now
 from webtest import Upload
 
 from chrono.agendas.models import (
@@ -25,6 +24,7 @@ from chrono.agendas.models import (
     UnavailabilityCalendar,
 )
 from chrono.manager.forms import TimePeriodExceptionForm
+from chrono.utils.timezone import localtime, make_aware, now
 from tests.utils import login
 
 pytestmark = pytest.mark.django_db
diff --git a/tests/manager/test_import_export.py b/tests/manager/test_import_export.py
index 698b13fb..eb513666 100644
--- a/tests/manager/test_import_export.py
+++ b/tests/manager/test_import_export.py
@@ -4,7 +4,6 @@ import json
 import freezegun
 import pytest
 from django.utils.encoding import force_str
-from django.utils.timezone import now
 from webtest import Upload
 
 from chrono.agendas.models import (
@@ -16,6 +15,7 @@ from chrono.agendas.models import (
     SharedCustodySettings,
     UnavailabilityCalendar,
 )
+from chrono.utils.timezone import now
 from tests.utils import login
 
 pytestmark = pytest.mark.django_db
diff --git a/tests/manager/test_meetings_agenda_options.py b/tests/manager/test_meetings_agenda_options.py
index 50dfb6af..70975933 100644
--- a/tests/manager/test_meetings_agenda_options.py
+++ b/tests/manager/test_meetings_agenda_options.py
@@ -4,7 +4,6 @@ import pytest
 from django.db import connection
 from django.test import override_settings
 from django.test.utils import CaptureQueriesContext
-from django.utils.timezone import localtime, now
 
 from chrono.agendas.models import (
     Agenda,
@@ -17,6 +16,7 @@ from chrono.agendas.models import (
     TimePeriodExceptionSource,
     UnavailabilityCalendar,
 )
+from chrono.utils.timezone import localtime, now
 from tests.utils import login
 
 pytestmark = pytest.mark.django_db
diff --git a/tests/manager/test_resource.py b/tests/manager/test_resource.py
index cbc70e87..aa4ac94f 100644
--- a/tests/manager/test_resource.py
+++ b/tests/manager/test_resource.py
@@ -4,9 +4,9 @@ import freezegun
 import pytest
 from django.db import connection
 from django.test.utils import CaptureQueriesContext
-from django.utils.timezone import localtime, make_aware, now
 
 from chrono.agendas.models import Agenda, Booking, Desk, Event, MeetingType, Resource, TimePeriod
+from chrono.utils.timezone import localtime, make_aware, now
 from tests.utils import login
 
 pytestmark = pytest.mark.django_db
diff --git a/tests/manager/test_shared_custody_agenda.py b/tests/manager/test_shared_custody_agenda.py
index f2d4b0e5..e6661311 100644
--- a/tests/manager/test_shared_custody_agenda.py
+++ b/tests/manager/test_shared_custody_agenda.py
@@ -4,7 +4,6 @@ import pytest
 from django.core.files.base import ContentFile
 from django.db import connection
 from django.test.utils import CaptureQueriesContext
-from django.utils.timezone import now
 
 from chrono.agendas.models import (
     Person,
@@ -16,6 +15,7 @@ from chrono.agendas.models import (
     TimePeriodExceptionGroup,
     UnavailabilityCalendar,
 )
+from chrono.utils.timezone import now
 from tests.utils import login
 
 pytestmark = pytest.mark.django_db
diff --git a/tests/manager/test_unavailability_calendar.py b/tests/manager/test_unavailability_calendar.py
index 567f9fcc..30e8733b 100644
--- a/tests/manager/test_unavailability_calendar.py
+++ b/tests/manager/test_unavailability_calendar.py
@@ -1,7 +1,6 @@
 import datetime
 
 import pytest
-from django.utils.timezone import localtime, make_aware, now
 
 from chrono.agendas.models import (
     Agenda,
@@ -12,6 +11,7 @@ from chrono.agendas.models import (
     TimePeriodException,
     UnavailabilityCalendar,
 )
+from chrono.utils.timezone import localtime, make_aware, now
 from tests.utils import login
 
 pytestmark = pytest.mark.django_db
diff --git a/tests/test_agendas.py b/tests/test_agendas.py
index 946c6694..9cf745c4 100644
--- a/tests/test_agendas.py
+++ b/tests/test_agendas.py
@@ -11,7 +11,6 @@ from django.core.management import call_command
 from django.db import IntegrityError, connection, transaction
 from django.db.models import Q
 from django.test import override_settings
-from django.utils.timezone import localtime, make_aware, now
 
 from chrono.agendas.models import (
     Agenda,
@@ -37,6 +36,7 @@ from chrono.agendas.models import (
     UnavailabilityCalendar,
     VirtualMember,
 )
+from chrono.utils.timezone import localtime, make_aware, now
 
 pytestmark = pytest.mark.django_db
 
diff --git a/tests/test_import_export.py b/tests/test_import_export.py
index 9f86d258..7bc130c0 100644
--- a/tests/test_import_export.py
+++ b/tests/test_import_export.py
@@ -13,7 +13,6 @@ from django.contrib.auth.models import Group
 from django.core.management import CommandError, call_command
 from django.test import override_settings
 from django.utils.encoding import force_bytes
-from django.utils.timezone import make_aware, now
 
 from chrono.agendas.models import (
     Agenda,
@@ -34,6 +33,7 @@ from chrono.agendas.models import (
     VirtualMember,
 )
 from chrono.manager.utils import import_site
+from chrono.utils.timezone import make_aware, now
 
 pytestmark = pytest.mark.django_db
 
@@ -1102,36 +1102,6 @@ def test_export_deleted_meetingtype(app):
     assert len(json.loads(output)['agendas'][0]['meetingtypes']) == 0
 
 
-def test_import_export_exception_dst_change(app):
-    agenda_meetings = Agenda.objects.create(label='Meetings Agenda', kind='meetings')
-    desk = Desk.objects.create(agenda=agenda_meetings, label='Desk')
-
-    # create exception starting on dst change
-    start = make_aware(datetime.datetime(2022, 10, 30, 2, 0), is_dst=True)
-    end = make_aware(datetime.datetime(2022, 10, 31, 2, 0))
-    TimePeriodException.objects.create(desk=desk, start_datetime=start, end_datetime=end)
-
-    output = get_output_of_command('export_site')
-    payload = json.loads(output)
-    assert payload['agendas'][0]['desks'][0]['exceptions'][0]['start_datetime'] == '2022-10-30 02:00:00'
-
-    import_site(data=payload, overwrite=True)
-    exception = TimePeriodException.objects.get()
-    assert exception.start_datetime == start
-    assert exception.end_datetime == end
-
-    start = exception.start_datetime = make_aware(datetime.datetime(2022, 10, 30, 2, 0), is_dst=False)
-    exception.save()
-    output = get_output_of_command('export_site')
-    payload = json.loads(output)
-    assert payload['agendas'][0]['desks'][0]['exceptions'][0]['start_datetime'] == '2022-10-30 02:00:00'
-
-    import_site(data=payload, overwrite=True)
-    exception = TimePeriodException.objects.get()
-    # dst was forced on import
-    assert exception.start_datetime == start - datetime.timedelta(hours=1)
-
-
 def test_import_export_agenda_update(app):
     agenda = Agenda.objects.create(label='Foo Bar', kind='meetings')
 
diff --git a/tests/test_misc.py b/tests/test_misc.py
index 0ffb2260..c74dbdb8 100644
--- a/tests/test_misc.py
+++ b/tests/test_misc.py
@@ -4,9 +4,9 @@ import pytest
 from django.db import IntegrityError, ProgrammingError, connection, transaction
 from django.db.migrations.executor import MigrationExecutor
 from django.test import override_settings
-from django.utils.timezone import now
 
 from chrono.agendas.models import Agenda, Booking, Desk, Event, MeetingType
+from chrono.utils.timezone import now
 
 pytestmark = pytest.mark.django_db
 
diff --git a/tests/test_time_periods.py b/tests/test_time_periods.py
index 92666d4a..0411e975 100644
--- a/tests/test_time_periods.py
+++ b/tests/test_time_periods.py
@@ -5,9 +5,9 @@ from django.db import IntegrityError, transaction
 from django.db.models import Q
 from django.test import override_settings
 from django.utils.encoding import force_str
-from django.utils.timezone import localtime, make_aware
 
 from chrono.agendas.models import Agenda, Desk, MeetingType, TimePeriod, TimePeriodException
+from chrono.utils.timezone import localtime, make_aware
 
 pytestmark = pytest.mark.django_db