feat(events): series-level gathering and deadline offsets

EventSeries gains gathering_offset and deadline_offset (durations before
the start). Each generated occurrence derives its gathering/deadline from
them (and clears them when unset); propagate_series pushes offset changes
to non-detached future occurrences. Surface them in the admin. 100%
coverage.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

events/admin.py

@@ -32,7 +32,8 @@ class EventSeriesAdmin(admin.ModelAdmin):
     autocomplete_fields = ["location", "opponent", "teams", "invited_members", "excluded_members"]
     fieldsets = [
         [None, {"fields": ["title", "kind"]}],
-        [_("Recurrence"), {"fields": ["rrule", "dtstart", "duration", "excluded_dates", "generated_until"]}],
+        [_("Recurrence"), {"fields": ["rrule", "dtstart", "excluded_dates", "generated_until"]}],
+        [_("Timing"), {"fields": ["duration", "gathering_offset", "deadline_offset"]}],
         [_("Audience"), {"fields": ["teams", "invited_members", "excluded_members"]}],
         [_("Where"), {"fields": ["location", "opponent"]}],
     ]

events/migrations/0006_event_series_offsets.py

@@ -0,0 +1,23 @@
+# Generated by Django 6.0.6 on 2026-07-12 16:03
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('events', '0005_event_series'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='eventseries',
+            name='deadline_offset',
+            field=models.DurationField(blank=True, help_text="How long before the start each occurrence's sign-up deadline is.", null=True, verbose_name='deadline offset'),
+        ),
+        migrations.AddField(
+            model_name='eventseries',
+            name='gathering_offset',
+            field=models.DurationField(blank=True, help_text="How long before the start each occurrence's gathering time is.", null=True, verbose_name='gathering offset'),
+        ),
+    ]

events/models.py

@@ -80,6 +80,8 @@ class EventSeries(ClubScopedModel):
     rrule = models.CharField(_("recurrence rule"), max_length=255, help_text=_("RFC 5545 RRULE, e.g. FREQ=WEEKLY;BYDAY=MO,WE."))
     dtstart = models.DateTimeField(_("first occurrence"))
     duration = models.DurationField(_("duration"), null=True, blank=True, help_text=_("Length of each occurrence; sets each event's end."))
+    gathering_offset = models.DurationField(_("gathering offset"), null=True, blank=True, help_text=_("How long before the start each occurrence's gathering time is."))
+    deadline_offset = models.DurationField(_("deadline offset"), null=True, blank=True, help_text=_("How long before the start each occurrence's sign-up deadline is."))
     excluded_dates = models.JSONField(_("excluded dates"), default=list, blank=True, help_text=_("ISO start datetimes of occurrences removed from the series (EXDATEs)."))
     generated_until = models.DateTimeField(_("generated until"), null=True, blank=True, help_text=_("Occurrences have been materialised up to this point."))
 

events/services/recurrence.py

@@ -45,8 +45,9 @@ def apply_template(series, event):
     event.title = series.title
     event.location = series.location
     event.opponent = series.opponent
-    if series.duration is not None:
-        event.end = event.start + series.duration
+    event.end = event.start + series.duration if series.duration is not None else None
+    event.gathering = event.start - series.gathering_offset if series.gathering_offset is not None else None
+    event.deadline = event.start - series.deadline_offset if series.deadline_offset is not None else None
     event.save()
 
     event.teams.set(series.teams.all())

events/tests.py

@@ -245,6 +245,24 @@ class GenerateOccurrencesTests(RecurrenceTestBase):
 
         self.assertEqual(series.occurrences.count(), 4)
 
+    def test_gathering_and_deadline_come_from_offsets(self):
+        series = self.make_series(gathering_offset=timedelta(minutes=30), deadline_offset=timedelta(days=1))
+
+        generate_occurrences(series, self.anchor + timedelta(days=30))
+
+        first = series.occurrences.order_by("start").first()
+        self.assertEqual(first.gathering, self.anchor - timedelta(minutes=30))
+        self.assertEqual(first.deadline, self.anchor - timedelta(days=1))
+
+    def test_without_offsets_gathering_and_deadline_are_blank(self):
+        series = self.make_series()
+
+        generate_occurrences(series, self.anchor + timedelta(days=30))
+
+        first = series.occurrences.order_by("start").first()
+        self.assertIsNone(first.gathering)
+        self.assertIsNone(first.deadline)
+
 
 class SingleOccurrenceTests(RecurrenceTestBase):
     def test_cancel_deletes_and_prevents_regeneration(self):
@@ -298,6 +316,17 @@ class SingleOccurrenceTests(RecurrenceTestBase):
         event = series.occurrences.order_by("start").first()
         self.assertIn(carol.id, set(event.attendances.values_list("member_id", flat=True)))
 
+    def test_propagation_updates_timing_offsets(self):
+        series = self.make_series()
+        generate_occurrences(series, self.anchor + timedelta(days=30))
+        series.gathering_offset = timedelta(minutes=45)
+        series.save()
+
+        propagate_series(series)
+
+        first = series.occurrences.order_by("start").first()
+        self.assertEqual(first.gathering, self.anchor - timedelta(minutes=45))
+
 
 class ExtendSeriesCommandTests(RecurrenceTestBase):
     def test_command_generates_occurrences(self):