diff --git a/addons/calendar/models/calendar.py b/addons/calendar/models/calendar.py
index 54ea446aed4..597bf760b95 100644
--- a/addons/calendar/models/calendar.py
+++ b/addons/calendar/models/calendar.py
@@ -454,6 +454,7 @@ class AlarmManager(models.AbstractModel):
             delta = delta.seconds + delta.days * 3600 * 24
 
             return {
+                'alarm_id': alarm.id,
                 'event_id': meeting.id,
                 'title': meeting.name,
                 'message': message,
diff --git a/addons/calendar/static/src/js/base_calendar.js b/addons/calendar/static/src/js/base_calendar.js
index 0a9dd625662..600ebd4b01a 100644
--- a/addons/calendar/static/src/js/base_calendar.js
+++ b/addons/calendar/static/src/js/base_calendar.js
@@ -38,12 +38,12 @@ var CalendarNotification = Notification.extend({
             },
 
             'click .link2recall': function() {
-                this.destroy(true);
+                this.close();
             },
 
             'click .link2showed': function() {
                 this._rpc({route: '/calendar/notify_ack'})
-                    .then(this.destroy.bind(this), this.destroy.bind(this));
+                    .then(this.close.bind(this, false), this.close.bind(this, false));
             },
         });
     },
@@ -57,22 +57,25 @@ WebClient.include({
         // Clear previously set timeouts and destroy currently displayed calendar notifications
         clearTimeout(this.get_next_calendar_notif_timeout);
         _.each(this.calendar_notif_timeouts, clearTimeout);
-        _.each(this.calendar_notif, function (notificationID) {
-            self.call('notification', 'close', notificationID, true);
-        });
         this.calendar_notif_timeouts = {};
-        this.calendar_notif = {};
 
         // For each notification, set a timeout to display it
         _.each(notifications, function(notif) {
-            self.calendar_notif_timeouts[notif.event_id] = setTimeout(function() {
+            var key = notif.event_id + ',' + notif.alarm_id;
+            if (key in self.calendar_notif) {
+                return;
+            }
+            self.calendar_notif_timeouts[key] = setTimeout(function () {
                 var notificationID = self.call('notification', 'notify', {
                     Notification: CalendarNotification,
                     title: notif.title,
                     message: notif.message,
                     eventID: notif.event_id,
+                    onClose: function () {
+                        delete self.calendar_notif[key];
+                    },
                 });
-                self.calendar_notif[notif.event_id] = notificationID;
+                self.calendar_notif[key] = notificationID;
             }, notif.timer * 1000);
             last_notif_timer = Math.max(last_notif_timer, notif.timer);
         });