diff --git a/aleksis/apps/alsijil/managers.py b/aleksis/apps/alsijil/managers.py
index 0eabc94d78bb261fa1b597bead2624ce4200d120..983a29b8d73196278afc3de7b1e25f484e62f02f 100644
--- a/aleksis/apps/alsijil/managers.py
+++ b/aleksis/apps/alsijil/managers.py
@@ -7,8 +7,10 @@ from django.db.models.query_utils import Q
 
 from calendarweek import CalendarWeek
 
-from aleksis.apps.chronos.managers import DateRangeQuerySetMixin
-from aleksis.core.managers import AlekSISBaseManagerWithoutMigrations, RecurrencePolymorphicManager
+from aleksis.core.managers import (
+    AlekSISBaseManagerWithoutMigrations,
+    RecurrencePolymorphicManager,
+)
 
 if TYPE_CHECKING:
     from aleksis.core.models import Group
@@ -42,7 +44,7 @@ class GroupRoleAssignmentManager(AlekSISBaseManagerWithoutMigrations):
     pass
 
 
-class GroupRoleAssignmentQuerySet(DateRangeQuerySetMixin, QuerySet):
+class GroupRoleAssignmentQuerySet(QuerySet):
     def within_dates(self, start: date, end: date):
         """Filter for all role assignments within a date range."""
         return self.filter(
diff --git a/aleksis/apps/alsijil/migrations/0007_personal_note_lesson_documentation_year.py b/aleksis/apps/alsijil/migrations/0007_personal_note_lesson_documentation_year.py
index 4cf8743b0ba5a2e16e0e1dcb491fe49b72dbb9c4..133cff82fb04e5a04e31dfe16f3efa58cc7f2133 100644
--- a/aleksis/apps/alsijil/migrations/0007_personal_note_lesson_documentation_year.py
+++ b/aleksis/apps/alsijil/migrations/0007_personal_note_lesson_documentation_year.py
@@ -1,8 +1,7 @@
 # Generated by Django 3.0.9 on 2020-08-15 09:39
 
 from django.db import migrations, models
-
-import aleksis.apps.chronos.util.date
+from django.utils import timezone
 
 
 def migrate_data(apps, schema_editor):
@@ -39,7 +38,7 @@ class Migration(migrations.Migration):
             model_name="lessondocumentation",
             name="year",
             field=models.IntegerField(
-                default=aleksis.apps.chronos.util.date.get_current_year,
+                default=lambda: timezone.now().year,
                 verbose_name="Year",
             ),
         ),
@@ -47,7 +46,7 @@ class Migration(migrations.Migration):
             model_name="personalnote",
             name="year",
             field=models.IntegerField(
-                default=aleksis.apps.chronos.util.date.get_current_year,
+                default=lambda: timezone.now().year,
                 verbose_name="Year",
             ),
         ),
diff --git a/aleksis/apps/alsijil/migrations/0009_group_roles.py b/aleksis/apps/alsijil/migrations/0009_group_roles.py
index 78f6f3666cb385a10e6d7101738e66b987fc68f2..ce978b3833b2c9b961c237ef24a4873710b5b0fd 100644
--- a/aleksis/apps/alsijil/migrations/0009_group_roles.py
+++ b/aleksis/apps/alsijil/migrations/0009_group_roles.py
@@ -44,6 +44,6 @@ class Migration(migrations.Migration):
                 'verbose_name': 'Group role assignment',
                 'verbose_name_plural': 'Group role assignments',
             },
-            bases=(aleksis.apps.chronos.managers.GroupPropertiesMixin, models.Model),
+            bases=(models.Model,),
         ),
     ]
diff --git a/aleksis/apps/alsijil/migrations/0010_events_extra_lessons.py b/aleksis/apps/alsijil/migrations/0010_events_extra_lessons.py
index 1c3bf9ec00c3d3242fd17cbc2ef60d1b097a4458..39878398d3aae13a0c0f870f4fb8f34d88c1450e 100644
--- a/aleksis/apps/alsijil/migrations/0010_events_extra_lessons.py
+++ b/aleksis/apps/alsijil/migrations/0010_events_extra_lessons.py
@@ -1,6 +1,5 @@
 # Generated by Django 3.1.5 on 2021-01-10 15:48
 
-import aleksis.apps.chronos.util.date
 from django.db import migrations, models
 import django.db.models.deletion
 
diff --git a/aleksis/apps/alsijil/models.py b/aleksis/apps/alsijil/models.py
index 8f0be3f18661dab3dfffea268c3498345ad435a2..eea2ea74955465d778e76bf5ae120fa9fec2e73b 100644
--- a/aleksis/apps/alsijil/models.py
+++ b/aleksis/apps/alsijil/models.py
@@ -23,9 +23,7 @@ from aleksis.apps.alsijil.managers import (
     GroupRoleQuerySet,
     ParticipationStatusManager,
 )
-from aleksis.apps.chronos.managers import GroupPropertiesMixin
 from aleksis.apps.chronos.models import LessonEvent
-from aleksis.apps.chronos.util.format import format_m2m
 from aleksis.apps.cursus.models import Course, Subject
 from aleksis.apps.kolego.models import Absence as KolegoAbsence
 from aleksis.apps.kolego.models import AbsenceReason
@@ -124,7 +122,7 @@ class Documentation(CalendarEvent):
         start_datetime = CalendarEvent.value_start_datetime(self)
         end_datetime = CalendarEvent.value_end_datetime(self)
         return (
-            f"{format_m2m(self.get_groups())} {self.get_subject()}"
+            f"{','.join(self.get_groups())} {self.get_subject()}"
             + f" {start_datetime} - {end_datetime}"
         )
 
@@ -557,7 +555,7 @@ class GroupRole(ExtensibleModel):
         return reverse("edit_group_role", args=[self.id])
 
 
-class GroupRoleAssignment(GroupPropertiesMixin, ExtensibleModel):
+class GroupRoleAssignment(ExtensibleModel):
     objects = GroupRoleAssignmentManager.from_queryset(GroupRoleAssignmentQuerySet)()
 
     role = models.ForeignKey(
diff --git a/aleksis/apps/alsijil/tasks.py b/aleksis/apps/alsijil/tasks.py
index fc4b79fd24871e6092ff7a1eb4376c0710adc662..53a902e24d69b91447d3abcdbde053939f91dfd2 100644
--- a/aleksis/apps/alsijil/tasks.py
+++ b/aleksis/apps/alsijil/tasks.py
@@ -8,7 +8,6 @@ from calendarweek import CalendarWeek
 from celery.result import allow_join_result
 from celery.states import SUCCESS
 
-from aleksis.apps.chronos.models import Event, ExtraLesson, LessonPeriod
 from aleksis.core.models import Group, PDFFile
 from aleksis.core.util.celery_progress import ProgressRecorder, recorded_task
 from aleksis.core.util.pdf import generate_pdf_from_template