diff --git a/calendar/base/content/calendar-month-view.xml b/calendar/base/content/calendar-month-view.xml
index 8cc06d705a52..f10f41d5dfe3 100644
--- a/calendar/base/content/calendar-month-view.xml
+++ b/calendar/base/content/calendar-month-view.xml
@@ -1302,8 +1302,6 @@
               this.calView.doDeleteItem(occ);
             }
           },
-          //XXXvv Alarm could, in theory, flash the event or something
-          onAlarm: function (aAlarmItem) { },
           onError: function (aErrNo, aMessage) { },
 
           //
diff --git a/calendar/base/content/calendar-multiday-view.xml b/calendar/base/content/calendar-multiday-view.xml
index 481d32b113c1..1dd7b477a1d1 100644
--- a/calendar/base/content/calendar-multiday-view.xml
+++ b/calendar/base/content/calendar-multiday-view.xml
@@ -1760,8 +1760,6 @@
 
                 this.calView.readjust();
             },
-            //XXXvv Alarm could, in theory, flash the event or something
-            onAlarm: function onAlarm(aAlarmItem) { },
             onError: function onError(aErrNo, aMessage) { },
 
             //
diff --git a/calendar/base/public/calICalendar.idl b/calendar/base/public/calICalendar.idl
index 368b96f557a1..e5c57fd2ce0e 100644
--- a/calendar/base/public/calICalendar.idl
+++ b/calendar/base/public/calICalendar.idl
@@ -374,7 +374,6 @@ interface calIObserver : nsISupports
   void onAddItem( in calIItemBase aItem );
   void onModifyItem( in calIItemBase aNewItem, in calIItemBase aOldItem );
   void onDeleteItem( in calIItemBase aDeletedItem );
-  void onAlarm( in calIItemBase aAlarmItem );
   void onError( in nsresult aErrNo, in AUTF8String aMessage );
 };
 
diff --git a/calendar/base/src/calAlarmService.js b/calendar/base/src/calAlarmService.js
index 8ac9eb5174bd..538ba6106c22 100644
--- a/calendar/base/src/calAlarmService.js
+++ b/calendar/base/src/calAlarmService.js
@@ -92,7 +92,6 @@ function calAlarmService() {
         onDeleteItem: function(aDeletedItem) {
             this.alarmService.removeAlarm(aDeletedItem);
         },
-        onAlarm: function(aAlarmItem) { },
         onError: function(aErrNo, aMessage) { }
     };
 
diff --git a/calendar/base/src/calCalendarManager.js b/calendar/base/src/calCalendarManager.js
index e246992bead0..773a65a1051d 100644
--- a/calendar/base/src/calCalendarManager.js
+++ b/calendar/base/src/calCalendarManager.js
@@ -383,7 +383,6 @@ function errorAnnouncer(calendar) {
         onAddItem: function(aItem) {},
         onModifyItem: function(aNewItem, aOldItem) {},
         onDeleteItem: function(aDeletedItem) {},
-        onAlarm: function(aAlarmItem) {},
         onError: function(aErrNo, aMessage) {
             announcer.announceError(aErrNo, aMessage);
         }
diff --git a/calendar/lightning/content/agenda-tree.js b/calendar/lightning/content/agenda-tree.js
index 6b026e7452bd..54ecaa346d55 100644
--- a/calendar/lightning/content/agenda-tree.js
+++ b/calendar/lightning/content/agenda-tree.js
@@ -451,7 +451,6 @@ function observer_onModifyItem(newItem, oldItem)
     this.onAddItem(newItem);
 };
 
-agendaTreeView.calendarObserver.onAlarm = function(item) {};
 agendaTreeView.calendarObserver.onError = function(errno, msg) {};
 
 agendaTreeView.calendarObserver.onCalendarAdded = 
diff --git a/calendar/lightning/content/calendar-management.js b/calendar/lightning/content/calendar-management.js
index 09c4948137d8..f7e0013c12bc 100644
--- a/calendar/lightning/content/calendar-management.js
+++ b/calendar/lightning/content/calendar-management.js
@@ -141,7 +141,6 @@ var ltnCompositeCalendarObserver = {
     onAddItem: function(aItem) { },
     onModifyItem: function(aNewItem, aOldItem) { },
     onDeleteItem: function(aDeletedItem) { },
-    onAlarm: function(aAlarmItem) { },
     onError: function(aErrNo, aMessage) { }
 };
 
diff --git a/calendar/lightning/content/calendar-todo-list.xml b/calendar/lightning/content/calendar-todo-list.xml
index 109401514fa6..5d4da4172a2c 100644
--- a/calendar/lightning/content/calendar-todo-list.xml
+++ b/calendar/lightning/content/calendar-todo-list.xml
@@ -59,10 +59,6 @@
                 this.todoList.addTodo(aNewItem);
             },
 
-            onAlarm: function onAlarm(aItem)
-            {
-            },
-
             onError: function onError(aErrNo, aMessage)
             {
             },
diff --git a/calendar/providers/composite/calCompositeCalendar.js b/calendar/providers/composite/calCompositeCalendar.js
index 71225a08557b..400b9a3ac4fc 100644
--- a/calendar/providers/composite/calCompositeCalendar.js
+++ b/calendar/providers/composite/calCompositeCalendar.js
@@ -90,10 +90,6 @@ calCompositeCalendarObserverHelper.prototype = {
         this.notifyObservers("onDeleteItem", arguments);
     },
 
-    onAlarm: function(aAlarmItem) {
-        this.notifyObservers("onAlarm", arguments);
-    },
-
     onError: function(aErrNo, aMessage) {
         this.notifyObservers("onError", arguments);
     }
diff --git a/calendar/providers/ics/calICSCalendar.js b/calendar/providers/ics/calICSCalendar.js
index 8f83988410de..86e7e9d4a1bf 100644
--- a/calendar/providers/ics/calICSCalendar.js
+++ b/calendar/providers/ics/calICSCalendar.js
@@ -808,10 +808,6 @@ calICSObserver.prototype = {
         for (var i = 0; i < this.mObservers.length; i++)
             this.mObservers[i].onDeleteItem(aDeletedItem);
     },
-    onAlarm: function(aAlarmItem) {
-        for (var i = 0; i < this.mObservers.length; i++)
-            this.mObservers[i].onAlarm(aAlarmItem);
-    },
 
     // Unless an error number is in this array, we consider it very bad, set
     // the calendar to readOnly, and give up.
diff --git a/calendar/resources/content/calendarManagement.js b/calendar/resources/content/calendarManagement.js
index 2d56fc0ba0b0..4f00e22957b8 100644
--- a/calendar/resources/content/calendarManagement.js
+++ b/calendar/resources/content/calendarManagement.js
@@ -157,7 +157,6 @@ var calCompositeCalendarObserver = {
     onAddItem: function(aItem) { },
     onModifyItem: function(aNewItem, aOldItem) { },
     onDeleteItem: function(aDeletedItem) { },
-    onAlarm: function(aAlarmItem) { },
     onError: function(aErrNo, aMessage) { }
 };
 
diff --git a/calendar/resources/content/unifinder.js b/calendar/resources/content/unifinder.js
index 46d54dc1cff9..b1ccccccb86a 100644
--- a/calendar/resources/content/unifinder.js
+++ b/calendar/resources/content/unifinder.js
@@ -225,7 +225,6 @@ var unifinderObserver = {
         }
     },
 
-    onAlarm: function(aAlarmItem) {},
     onError: function(aErrNo, aMessage) {},
     
     // calICompositeObserver:
diff --git a/calendar/resources/content/unifinderToDo.js b/calendar/resources/content/unifinderToDo.js
index 50013fa22bf7..d26ee879cb66 100644
--- a/calendar/resources/content/unifinderToDo.js
+++ b/calendar/resources/content/unifinderToDo.js
@@ -100,7 +100,6 @@ var unifinderToDoDataSourceObserver =
             !this.mInBatch)
             toDoUnifinderRefresh();
     },
-    onAlarm: function(aAlarmItem) {},
     onError: function(aErrNo, aMessage) {},
 
     // calICompositeObserver: