diff --git a/shiftregister/app/models.py b/shiftregister/app/models.py
index 2e80da6..76146d9 100644
--- a/shiftregister/app/models.py
+++ b/shiftregister/app/models.py
@@ -88,13 +88,6 @@ class ShiftRegistration(models.Model):
         self.reminder_sent = True
         self.save()
 
-    def get_unnotified_registrations():
-        return ShiftRegistration.objects.filter(
-            reminder_sent=False,
-            shift__start_at__lte=timezone.now()
-            + global_preferences["helper__reminder_time"],
-        )
-
     def __str__(self):
         return f"{self.helper.name}: {self.shift}"
 
diff --git a/shiftregister/app/tasks.py b/shiftregister/app/tasks.py
index 98a244d..02dce9e 100644
--- a/shiftregister/app/tasks.py
+++ b/shiftregister/app/tasks.py
@@ -1,5 +1,5 @@
 from celery import shared_task
-from .models import Message
+from .models import Message, ShiftRegistration
 from django.db import transaction
 from django.utils import timezone
 from dynamic_preferences.registries import global_preferences_registry
@@ -36,3 +36,14 @@ def send_message(msgid):
         print(f"TODO: send message @{msg.to.phone} {msg.text}")
         msg.sent_at = timezone.now()
         msg.save()
+
+
+@shared_task
+def send_reminders():
+    with transaction.atomic():
+        for reg in ShiftRegistration.objects.select_for_update().filter(
+            reminder_sent=False,
+            shift__start_at__lte=timezone.now()
+            + global_preferences["helper__reminder_time"],
+        ):
+            reg.send_reminder()
diff --git a/shiftregister/settings.py b/shiftregister/settings.py
index e56c8a1..b30b841 100644
--- a/shiftregister/settings.py
+++ b/shiftregister/settings.py
@@ -154,6 +154,14 @@ CELERY_BEAT_SCHEDULE = {
         "task": "shiftregister.importer.tasks.import_shifts",
         "schedule": float(getenv("SHIFT_IMPORT_INTERVAL", 60.0)),  # seconds
     },
+    "send-messages-every-120-seconds": {
+        "task": "shiftregister.app.tasks.send_messages",
+        "schedule": float(getenv("SHIFT_IMPORT_INTERVAL", 120.0)),  # seconds
+    },
+    "send-reminders-every-300-seconds": {
+        "task": "shiftregister.app.tasks.send_reminders",
+        "schedule": float(getenv("SHIFT_IMPORT_INTERVAL", 300.0)),  # seconds
+    },
 }
 
 CELERY_BEAT_SCHEDULE_FILENAME = str(BASE_DIR / "storage" / "celerybeat-schedule")