diff --git a/server/backend/cron/alarm.go b/server/backend/cron/alarm.go
index aa6cf3f1..7162878b 100644
--- a/server/backend/cron/alarm.go
+++ b/server/backend/cron/alarm.go
@@ -1,7 +1,64 @@
 package cron
 
-//lint:ignore U1000 stub
+import (
+	"github.com/TUM-Dev/Campus-Backend/server/model"
+	log "github.com/sirupsen/logrus"
+	"gorm.io/gorm"
+)
+
 func (c *CronService) alarmCron() error {
-	// TODO: implement
+	return notifyAllUsers(c.db, sendGCMNotification)
+}
+
+func sendGCMNotification(*[]model.Devices) error {
+	log.Trace("sendGCMNotification")
+	return nil
+}
+
+func notifyAllUsers(db *gorm.DB, callbacks ...func(*[]model.Devices) error) error {
+	var pendingNotifications []model.Notification
+	if err := db.
+		Joins("notification_confirmation").
+		Where("notification_confirmation.sent = ?", false).
+		Group("notification").
+		Find(&pendingNotifications).Error; err != nil {
+		log.WithError(err).Error("failed to get pending notifications from the db")
+		return err
+	}
+	for _, pending := range pendingNotifications {
+		// Get a few targets
+		var targets []model.Devices
+		if err := db.
+			Distinct("device").
+			Where("notification = ?", pending.Notification).
+			Where("gcmStatus IS NULL").
+			Where("gcmToken IS NOT NULL").
+			Joins("notification_confirmation").
+			Where("notification_confirmation.sent = ?", false).
+			Limit(998).
+			Find(&targets).
+			Error; err != nil {
+			log.WithError(err).Error("failed to get devices which should receive the notification")
+			continue
+		}
+		if len(targets) > 0 {
+			for _, callback := range callbacks {
+				if err := callback(&targets); err != nil {
+					log.WithError(err).Error("callback failed")
+					continue
+				}
+			}
+			// mark as sent for these targets
+			if err := db.
+				Model(&model.NotificationConfirmation{}).
+				Where("notification = ?", pending.Notification).
+				Where("device IN ?", targets).
+				Update("sent", true).
+				Error; err != nil {
+				log.WithError(err).Error("failed to update notification_confirmation")
+				continue
+			}
+		}
+	}
 	return nil
 }
diff --git a/server/backend/cron/cronjobs.go b/server/backend/cron/cronjobs.go
index 75f4752d..3211d328 100644
--- a/server/backend/cron/cronjobs.go
+++ b/server/backend/cron/cronjobs.go
@@ -29,9 +29,9 @@ const (
 	CanteenHeadcount = "canteenHeadCount"
 	MovieType        = "movie"
 	FeedbackEmail    = "feedbackEmail"
+	AlarmType        = "alarm"
 
-	/* MensaType      = "mensa"
-	AlarmType      = "alarm" */
+	// MensaType      = "mensa"
 )
 
 func New(db *gorm.DB) *CronService {
@@ -57,6 +57,7 @@ func (c *CronService) Run() error {
 				CanteenHeadcount,
 				MovieType,
 				FeedbackEmail,
+				AlarmType,
 			).
 			Scan(&res)
 
@@ -96,6 +97,8 @@ func (c *CronService) Run() error {
 				g.Go(func() error { return c.canteenHeadCountCron() })
 			case FeedbackEmail:
 				g.Go(func() error { return c.feedbackEmailCron() })
+			case AlarmType:
+				g.Go(func() error { return c.alarmCron() })
 			}
 		}