Fix migration containing datetime

website/events/migrations/0025_auto_20180112_1214.py

+# Generated by Django 2.0.1 on 2018-01-12 11:14
+
+from django.db import migrations, models
+import django.db.models.deletion
+import events.models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('events', '0024_auto_20180111_1039'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='registration',
+            name='member',
+            field=models.ForeignKey(blank=True, limit_choices_to=events.models.registration_member_choices_limit, null=True, on_delete=django.db.models.deletion.CASCADE, to='members.Member'),
+        ),
+    ]

website/events/models.py

@@ -258,6 +258,11 @@ class Event(models.Model, metaclass=ModelTranslateMeta):
         )
 
 
+def registration_member_choices_limit():
+    return (Q(membership__until__isnull=True) |
+            Q(membership__until__gt=timezone.now().date()))
+
+
 class Registration(models.Model):
     """Event registrations"""
 
@@ -276,8 +281,7 @@ class Registration(models.Model):
         'members.Member', models.CASCADE,
         blank=True,
         null=True,
-        limit_choices_to=(Q(membership__until__isnull=True) |
-                          Q(membership__until__gt=timezone.now().date()))
+        limit_choices_to=registration_member_choices_limit
     )
 
     name = models.CharField(