diff --git a/aleksis/apps/chronos/migrations/0015_managed_by_site.py b/aleksis/apps/chronos/migrations/0015_managed_by_site.py
new file mode 100644
index 0000000000000000000000000000000000000000..001528f86f0b981003a27b32558df0f25ea5f1e3
--- /dev/null
+++ b/aleksis/apps/chronos/migrations/0015_managed_by_site.py
@@ -0,0 +1,390 @@
+# Generated by Django 4.2.3 on 2023-07-31 08:21
+
+import aleksis.core.managers
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+ dependencies = [
+ ("sites", "0002_alter_domain_unique"),
+ ("chronos", "0014_lessonevent"),
+ ]
+
+ operations = [
+ migrations.AlterModelManagers(
+ name="absencereason",
+ managers=[
+ ("objects", aleksis.core.managers.AlekSISBaseManager()),
+ ],
+ ),
+ migrations.AlterModelManagers(
+ name="automaticplan",
+ managers=[],
+ ),
+ migrations.AlterModelManagers(
+ name="subject",
+ managers=[
+ ("objects", aleksis.core.managers.AlekSISBaseManager()),
+ ],
+ ),
+ migrations.AlterModelManagers(
+ name="supervisionarea",
+ managers=[
+ ("objects", aleksis.core.managers.AlekSISBaseManager()),
+ ],
+ ),
+ migrations.AddField(
+ model_name="absence",
+ name="managed_by_app_label",
+ field=models.CharField(
+ blank=True,
+ editable=False,
+ max_length=255,
+ verbose_name="App label of app responsible for managing this instance",
+ ),
+ ),
+ migrations.AddField(
+ model_name="absencereason",
+ name="managed_by_app_label",
+ field=models.CharField(
+ blank=True,
+ editable=False,
+ max_length=255,
+ verbose_name="App label of app responsible for managing this instance",
+ ),
+ ),
+ migrations.AddField(
+ model_name="break",
+ name="managed_by_app_label",
+ field=models.CharField(
+ blank=True,
+ editable=False,
+ max_length=255,
+ verbose_name="App label of app responsible for managing this instance",
+ ),
+ ),
+ migrations.AddField(
+ model_name="event",
+ name="managed_by_app_label",
+ field=models.CharField(
+ blank=True,
+ editable=False,
+ max_length=255,
+ verbose_name="App label of app responsible for managing this instance",
+ ),
+ ),
+ migrations.AddField(
+ model_name="exam",
+ name="managed_by_app_label",
+ field=models.CharField(
+ blank=True,
+ editable=False,
+ max_length=255,
+ verbose_name="App label of app responsible for managing this instance",
+ ),
+ ),
+ migrations.AddField(
+ model_name="extralesson",
+ name="managed_by_app_label",
+ field=models.CharField(
+ blank=True,
+ editable=False,
+ max_length=255,
+ verbose_name="App label of app responsible for managing this instance",
+ ),
+ ),
+ migrations.AddField(
+ model_name="holiday",
+ name="managed_by_app_label",
+ field=models.CharField(
+ blank=True,
+ editable=False,
+ max_length=255,
+ verbose_name="App label of app responsible for managing this instance",
+ ),
+ ),
+ migrations.AddField(
+ model_name="lesson",
+ name="managed_by_app_label",
+ field=models.CharField(
+ blank=True,
+ editable=False,
+ max_length=255,
+ verbose_name="App label of app responsible for managing this instance",
+ ),
+ ),
+ migrations.AddField(
+ model_name="lessonperiod",
+ name="managed_by_app_label",
+ field=models.CharField(
+ blank=True,
+ editable=False,
+ max_length=255,
+ verbose_name="App label of app responsible for managing this instance",
+ ),
+ ),
+ migrations.AddField(
+ model_name="lessonsubstitution",
+ name="managed_by_app_label",
+ field=models.CharField(
+ blank=True,
+ editable=False,
+ max_length=255,
+ verbose_name="App label of app responsible for managing this instance",
+ ),
+ ),
+ migrations.AddField(
+ model_name="subject",
+ name="managed_by_app_label",
+ field=models.CharField(
+ blank=True,
+ editable=False,
+ max_length=255,
+ verbose_name="App label of app responsible for managing this instance",
+ ),
+ ),
+ migrations.AddField(
+ model_name="supervision",
+ name="managed_by_app_label",
+ field=models.CharField(
+ blank=True,
+ editable=False,
+ max_length=255,
+ verbose_name="App label of app responsible for managing this instance",
+ ),
+ ),
+ migrations.AddField(
+ model_name="supervisionarea",
+ name="managed_by_app_label",
+ field=models.CharField(
+ blank=True,
+ editable=False,
+ max_length=255,
+ verbose_name="App label of app responsible for managing this instance",
+ ),
+ ),
+ migrations.AddField(
+ model_name="supervisionsubstitution",
+ name="managed_by_app_label",
+ field=models.CharField(
+ blank=True,
+ editable=False,
+ max_length=255,
+ verbose_name="App label of app responsible for managing this instance",
+ ),
+ ),
+ migrations.AddField(
+ model_name="timeperiod",
+ name="managed_by_app_label",
+ field=models.CharField(
+ blank=True,
+ editable=False,
+ max_length=255,
+ verbose_name="App label of app responsible for managing this instance",
+ ),
+ ),
+ migrations.AddField(
+ model_name="validityrange",
+ name="managed_by_app_label",
+ field=models.CharField(
+ blank=True,
+ editable=False,
+ max_length=255,
+ verbose_name="App label of app responsible for managing this instance",
+ ),
+ ),
+ migrations.AlterField(
+ model_name="absence",
+ name="site",
+ field=models.ForeignKey(
+ default=1,
+ editable=False,
+ on_delete=django.db.models.deletion.CASCADE,
+ related_name="+",
+ to="sites.site",
+ ),
+ ),
+ migrations.AlterField(
+ model_name="absencereason",
+ name="site",
+ field=models.ForeignKey(
+ default=1,
+ editable=False,
+ on_delete=django.db.models.deletion.CASCADE,
+ related_name="+",
+ to="sites.site",
+ ),
+ ),
+ migrations.AlterField(
+ model_name="break",
+ name="site",
+ field=models.ForeignKey(
+ default=1,
+ editable=False,
+ on_delete=django.db.models.deletion.CASCADE,
+ related_name="+",
+ to="sites.site",
+ ),
+ ),
+ migrations.AlterField(
+ model_name="event",
+ name="site",
+ field=models.ForeignKey(
+ default=1,
+ editable=False,
+ on_delete=django.db.models.deletion.CASCADE,
+ related_name="+",
+ to="sites.site",
+ ),
+ ),
+ migrations.AlterField(
+ model_name="exam",
+ name="site",
+ field=models.ForeignKey(
+ default=1,
+ editable=False,
+ on_delete=django.db.models.deletion.CASCADE,
+ related_name="+",
+ to="sites.site",
+ ),
+ ),
+ migrations.AlterField(
+ model_name="extralesson",
+ name="site",
+ field=models.ForeignKey(
+ default=1,
+ editable=False,
+ on_delete=django.db.models.deletion.CASCADE,
+ related_name="+",
+ to="sites.site",
+ ),
+ ),
+ migrations.AlterField(
+ model_name="holiday",
+ name="site",
+ field=models.ForeignKey(
+ default=1,
+ editable=False,
+ on_delete=django.db.models.deletion.CASCADE,
+ related_name="+",
+ to="sites.site",
+ ),
+ ),
+ migrations.AlterField(
+ model_name="lesson",
+ name="site",
+ field=models.ForeignKey(
+ default=1,
+ editable=False,
+ on_delete=django.db.models.deletion.CASCADE,
+ related_name="+",
+ to="sites.site",
+ ),
+ ),
+ migrations.AlterField(
+ model_name="lessonperiod",
+ name="site",
+ field=models.ForeignKey(
+ default=1,
+ editable=False,
+ on_delete=django.db.models.deletion.CASCADE,
+ related_name="+",
+ to="sites.site",
+ ),
+ ),
+ migrations.AlterField(
+ model_name="lessonsubstitution",
+ name="site",
+ field=models.ForeignKey(
+ default=1,
+ editable=False,
+ on_delete=django.db.models.deletion.CASCADE,
+ related_name="+",
+ to="sites.site",
+ ),
+ ),
+ migrations.AlterField(
+ model_name="subject",
+ name="site",
+ field=models.ForeignKey(
+ default=1,
+ editable=False,
+ on_delete=django.db.models.deletion.CASCADE,
+ related_name="+",
+ to="sites.site",
+ ),
+ ),
+ migrations.AlterField(
+ model_name="supervision",
+ name="site",
+ field=models.ForeignKey(
+ default=1,
+ editable=False,
+ on_delete=django.db.models.deletion.CASCADE,
+ related_name="+",
+ to="sites.site",
+ ),
+ ),
+ migrations.AlterField(
+ model_name="supervisionarea",
+ name="site",
+ field=models.ForeignKey(
+ default=1,
+ editable=False,
+ on_delete=django.db.models.deletion.CASCADE,
+ related_name="+",
+ to="sites.site",
+ ),
+ ),
+ migrations.AlterField(
+ model_name="supervisionsubstitution",
+ name="site",
+ field=models.ForeignKey(
+ default=1,
+ editable=False,
+ on_delete=django.db.models.deletion.CASCADE,
+ related_name="+",
+ to="sites.site",
+ ),
+ ),
+ migrations.AlterField(
+ model_name="timeperiod",
+ name="site",
+ field=models.ForeignKey(
+ default=1,
+ editable=False,
+ on_delete=django.db.models.deletion.CASCADE,
+ related_name="+",
+ to="sites.site",
+ ),
+ ),
+ migrations.AlterField(
+ model_name="timeperiod",
+ name="weekday",
+ field=models.PositiveSmallIntegerField(
+ choices=[
+ (0, "Monday"),
+ (1, "Tuesday"),
+ (2, "Wednesday"),
+ (3, "Thursday"),
+ (4, "Friday"),
+ (5, "Saturday"),
+ (6, "Sunday"),
+ ],
+ verbose_name="Week day",
+ ),
+ ),
+ migrations.AlterField(
+ model_name="validityrange",
+ name="site",
+ field=models.ForeignKey(
+ default=1,
+ editable=False,
+ on_delete=django.db.models.deletion.CASCADE,
+ related_name="+",
+ to="sites.site",
+ ),
+ ),
+ ]