add event_start setting to filter day navigation

shiftregister/app/dynamic_preferences_registry.py

@@ -78,3 +78,11 @@ class FallbackQuota(types.FloatPreference):
     section = helper
     name = "fallback_quota"
     default = 0.7
+
+
+@global_preferences_registry.register
+class EventStartAt(types.DateTimePreference):
+    section = helper
+    name = "event_start_at"
+    default = datetime.datetime.now()
+    help_text = "The start date and time of the event. Date navigation will only show days after this time."

shiftregister/app/views.py

@@ -26,7 +26,12 @@ def index(request):
 
     days = cache.get("event_days")
     if not days:
-        days = Shift.objects.filter(deleted=False).datetimes("start_at", "day").all()
+        event_start = global_preferences["helper__event_start_at"]
+        days = (
+            Shift.objects.filter(deleted=False, start_at__gte=event_start)
+            .datetimes("start_at", "day")
+            .all()
+        )
         cache.set("event_days", days)
 
     context = {