--- a/b2g/app/b2g.js
+++ b/b2g/app/b2g.js
@@ -373,16 +373,19 @@ pref("dom.ipc.tabs.disabled", false);
 pref("dom.ipc.browser_frames.oop_by_default", false);
 
 // Temporary permission hack for WebSMS
 pref("dom.sms.enabled", true);
 
 // Temporary permission hack for WebContacts
 pref("dom.mozContacts.enabled", true);
 
+// WebAlarms
+pref("dom.mozAlarms.enabled", true);
+
 // WebSettings
 pref("dom.mozSettings.enabled", true);
 
 // Ignore X-Frame-Options headers.
 pref("b2g.ignoreXFrameOptions", true);
 
 // controls if we want camera support
 pref("device.camera.enabled", true);

--- a/b2g/chrome/content/shell.js
+++ b/b2g/chrome/content/shell.js
@@ -46,17 +46,17 @@ XPCOMUtils.defineLazyGetter(this, 'Debug
 // until we have a proper security model, add some rights to
 // the pre-installed web applications
 // XXX never grant 'content-camera' to non-gaia apps
 function addPermissions(urls) {
   let permissions = [
     'indexedDB', 'indexedDB-unlimited', 'webapps-manage', 'offline-app', 'pin-app',
     'websettings-read', 'websettings-readwrite',
     'content-camera', 'webcontacts-manage', 'wifi-manage', 'desktop-notification',
-    'geolocation', 'device-storage'
+    'geolocation', 'device-storage', 'alarms'
   ];
   urls.forEach(function(url) {
     url = url.trim();
     let uri = Services.io.newURI(url, null, null);
     let allow = Ci.nsIPermissionManager.ALLOW_ACTION;
 
     permissions.forEach(function(permission) {
       Services.perms.add(uri, permission, allow);

--- a/b2g/installer/package-manifest.in
+++ b/b2g/installer/package-manifest.in
@@ -156,16 +156,17 @@
 @BINPATH@/components/dom_system_gonk.xpt
 #endif
 @BINPATH@/components/dom_battery.xpt
 #ifdef MOZ_B2G_BT
 @BINPATH@/components/dom_bluetooth.xpt
 #endif
 @BINPATH@/components/dom_canvas.xpt
 @BINPATH@/components/dom_contacts.xpt
+@BINPATH@/components/dom_alarm.xpt
 @BINPATH@/components/dom_core.xpt
 @BINPATH@/components/dom_css.xpt
 @BINPATH@/components/dom_devicestorage.xpt
 @BINPATH@/components/dom_events.xpt
 @BINPATH@/components/dom_file.xpt
 @BINPATH@/components/dom_geolocation.xpt
 @BINPATH@/components/dom_media.xpt
 @BINPATH@/components/dom_network.xpt
@@ -312,16 +313,18 @@
 
 ; JavaScript components
 @BINPATH@/components/ConsoleAPI.manifest
 @BINPATH@/components/ConsoleAPI.js
 @BINPATH@/components/BrowserElementParent.manifest
 @BINPATH@/components/BrowserElementParent.js
 @BINPATH@/components/ContactManager.js
 @BINPATH@/components/ContactManager.manifest
+@BINPATH@/components/AlarmsManager.js
+@BINPATH@/components/AlarmsManager.manifest
 @BINPATH@/components/FeedProcessor.manifest
 @BINPATH@/components/FeedProcessor.js
 @BINPATH@/components/BrowserFeeds.manifest
 @BINPATH@/components/FeedConverter.js
 @BINPATH@/components/FeedWriter.js
 @BINPATH@/components/fuelApplication.manifest
 @BINPATH@/components/fuelApplication.js
 @BINPATH@/components/WebContentConverter.js

--- a/browser/installer/package-manifest.in
+++ b/browser/installer/package-manifest.in
@@ -167,16 +167,17 @@
 @BINPATH@/components/dom_system_gonk.xpt
 #endif
 @BINPATH@/components/dom_battery.xpt
 #ifdef MOZ_B2G_BT
 @BINPATH@/components/dom_bluetooth.xpt
 #endif
 @BINPATH@/components/dom_canvas.xpt
 @BINPATH@/components/dom_contacts.xpt
+@BINPATH@/components/dom_alarm.xpt
 @BINPATH@/components/dom_core.xpt
 @BINPATH@/components/dom_css.xpt
 @BINPATH@/components/dom_devicestorage.xpt
 @BINPATH@/components/dom_events.xpt
 @BINPATH@/components/dom_file.xpt
 @BINPATH@/components/dom_geolocation.xpt
 @BINPATH@/components/dom_media.xpt
 @BINPATH@/components/dom_network.xpt
@@ -466,16 +467,18 @@
 @BINPATH@/components/SettingsManager.manifest
 @BINPATH@/components/Webapps.js
 @BINPATH@/components/Webapps.manifest
 @BINPATH@/components/AppsService.js
 @BINPATH@/components/AppsService.manifest
 
 @BINPATH@/components/ContactManager.js
 @BINPATH@/components/ContactManager.manifest
+@BINPATH@/components/AlarmsManager.js
+@BINPATH@/components/AlarmsManager.manifest
 #ifdef ENABLE_MARIONETTE
 @BINPATH@/chrome/marionette@JAREXT@
 @BINPATH@/chrome/marionette.manifest
 @BINPATH@/components/MarionetteComponents.manifest
 @BINPATH@/components/marionettecomponent.js
 #endif
 
 ; Modules

--- a/dom/Makefile.in
+++ b/dom/Makefile.in
@@ -45,16 +45,17 @@ DIRS += \
 
 DIRS += \
   apps \
   base \
   bindings \
   battery \
   browser-element \
   contacts \
+  alarm \
   devicestorage \
   file \
   media \
   messages \
   power \
   settings \
   sms \
   mms \

new file mode 100644
--- /dev/null
+++ b/dom/alarm/AlarmsManager.js
@@ -0,0 +1,75 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const { classes: Cc, interfaces: Ci, utils: Cu, results: Cr } = Components;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/DOMRequestHelper.jsm");
+
+const ALARMSMANAGER_CONTRACTID = "@mozilla.org/alarmsManager;1";
+const ALARMSMANAGER_CID        = Components.ID("{fea1e884-9b05-11e1-9b64-87a7016c3860}");
+const nsIDOMMozAlarmsManager   = Ci.nsIDOMMozAlarmsManager;
+const nsIClassInfo             = Ci.nsIClassInfo;
+
+function AlarmsManager()
+{
+}
+
+AlarmsManager.prototype = {
+
+  __proto__: DOMRequestIpcHelper.prototype,
+
+  classID : ALARMSMANAGER_CID,
+
+  QueryInterface : XPCOMUtils.generateQI([nsIDOMMozAlarmsManager, Ci.nsIDOMGlobalPropertyInitializer]),
+
+  classInfo : XPCOMUtils.generateCI({ classID: ALARMSMANAGER_CID,
+                                      contractID: ALARMSMANAGER_CONTRACTID,
+                                      classDescription: "AlarmsManager",
+                                      interfaces: [nsIDOMMozAlarmsManager],
+                                      flags: nsIClassInfo.DOM_OBJECT }),
+
+  add: function add(aDate, aRespectTimezone, aData) {
+    return null;
+  },
+
+  remove: function remove(aId) {
+    return;
+  },
+
+  getAll: function getAll() {
+    return null;
+  },
+
+  // nsIDOMGlobalPropertyInitializer implementation
+  init: function init(aWindow) {
+    // Set navigator.mozAlarms to null.
+    if (!Services.prefs.getBoolPref("dom.mozAlarms.enabled"))
+      return null;
+
+    let principal = aWindow.document.nodePrincipal;
+    let secMan = Cc["@mozilla.org/scriptsecuritymanager;1"].getService(Ci.nsIScriptSecurityManager);
+
+    let perm = principal == secMan.getSystemPrincipal() ? 
+      Ci.nsIPermissionManager.ALLOW_ACTION : Services.perms.testExactPermission(principal.URI, "alarms");
+
+    // Only pages with perm set can use the alarms.
+    this.hasPrivileges = perm == Ci.nsIPermissionManager.ALLOW_ACTION;
+
+    if (!this.hasPrivileges)
+      return null;
+
+    // Add the valid messages to be listened.
+    this.initHelper(aWindow, []);
+  },
+
+  // Called from DOMRequestIpcHelper.
+  uninit: function uninit() {
+  },
+}
+
+const NSGetFactory = XPCOMUtils.generateNSGetFactory([AlarmsManager])

new file mode 100644
--- /dev/null
+++ b/dom/alarm/AlarmsManager.manifest
@@ -0,0 +1,3 @@
+component {fea1e884-9b05-11e1-9b64-87a7016c3860} AlarmsManager.js
+contract @mozilla.org/alarmsManager;1 {fea1e884-9b05-11e1-9b64-87a7016c3860}
+category JavaScript-navigator-property mozAlarms @mozilla.org/alarmsManager;1

new file mode 100644
--- /dev/null
+++ b/dom/alarm/Makefile.in
@@ -0,0 +1,33 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DEPTH       = ../..
+topsrcdir   = @top_srcdir@
+srcdir      = @srcdir@
+VPATH       = @srcdir@
+
+include $(DEPTH)/config/autoconf.mk
+
+MODULE              = dom
+XPIDL_MODULE        = dom_alarm
+LIBRARY_NAME        = domalarm_s
+LIBXUL_LIBRARY      = 1
+
+include $(topsrcdir)/dom/dom-config.mk
+
+EXTRA_COMPONENTS =       \
+  AlarmsManager.js       \
+  AlarmsManager.manifest \
+  $(NULL)
+
+XPIDLSRCS =               \
+  nsIDOMAlarmsManager.idl \
+  $(NULL)
+
+ifdef ENABLE_TESTS
+DIRS += test
+endif
+
+include $(topsrcdir)/config/config.mk
+include $(topsrcdir)/config/rules.mk

new file mode 100644
--- /dev/null
+++ b/dom/alarm/nsIDOMAlarmsManager.idl
@@ -0,0 +1,15 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "domstubs.idl"
+
+interface nsIDOMDOMRequest;
+
+[scriptable, uuid(fea1e884-9b05-11e1-9b64-87a7016c3860)]
+interface nsIDOMMozAlarmsManager : nsISupports
+{
+  nsIDOMDOMRequest getAll();
+  nsIDOMDOMRequest add(in jsval date, in DOMString respectTimezone, [optional] in jsval data);
+  void remove(in unsigned long id);
+};

new file mode 100644
--- /dev/null
+++ b/dom/alarm/test/Makefile.in
@@ -0,0 +1,25 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DEPTH            = ../../..
+topsrcdir        = @top_srcdir@
+srcdir           = @srcdir@
+VPATH            = @srcdir@
+
+relativesrcdir   = dom/alarm/test
+
+include $(DEPTH)/config/autoconf.mk
+
+DIRS = \
+  $(NULL)
+
+include $(topsrcdir)/config/rules.mk
+
+_TEST_FILES = \
+  test_alarm_permitted_app.html \
+  test_alarm_non_permitted_app.html \
+  $(NULL)
+
+libs:: $(_TEST_FILES)
+	$(INSTALL) $(foreach f,$^,"$f") $(DEPTH)/_tests/testing/mochitest/tests/$(relativesrcdir)

new file mode 100644
--- /dev/null
+++ b/dom/alarm/test/test_alarm_non_permitted_app.html
@@ -0,0 +1,32 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test Non-Permitted Application for Alarm API</title>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<p id="display"></p>
+<div id="content" style="display: none"></div>
+<pre id="test">
+<script type="application/javascript">
+
+"use strict";
+
+SimpleTest.waitForExplicitFinish();
+
+SpecialPowers.pushPrefEnv({"set": [["dom.mozAlarms.enabled", true]]}, function() {
+  SpecialPowers.removePermission("alarms", document);
+
+  var mozAlarms = navigator.mozAlarms;
+
+  ok('mozAlarms' in navigator, "navigator.mozAlarms should exist");
+  is(mozAlarms, null, "navigator.mozAlarms should return null");
+
+  SimpleTest.finish();
+});
+
+</script>
+</pre>
+</body>
+</html>

new file mode 100644
--- /dev/null
+++ b/dom/alarm/test/test_alarm_permitted_app.html
@@ -0,0 +1,35 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test Permitted Application for Alarm API</title>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<p id="display"></p>
+<div id="content" style="display: none"></div>
+<pre id="test">
+<script type="application/javascript">
+
+"use strict";
+
+SimpleTest.waitForExplicitFinish();
+
+SpecialPowers.pushPrefEnv({"set": [["dom.mozAlarms.enabled", true]]}, function() {
+  SpecialPowers.addPermission("alarms", true, document);
+
+  var mozAlarms = navigator.mozAlarms;
+
+  ok('mozAlarms' in navigator, "navigator.mozAlarms should exist");
+  ok(mozAlarms, "navigator.mozAlarms should return an object");
+  ok(mozAlarms instanceof Components.interfaces.nsIDOMMozAlarmsManager,
+    "navigator.mozAlarms should be an nsIDOMMozAlarmsManager object");
+
+  SpecialPowers.removePermission("alarms", document);
+  SimpleTest.finish();
+});
+
+</script>
+</pre>
+</body>
+</html>

--- a/dom/dom-config.mk
+++ b/dom/dom-config.mk
@@ -7,16 +7,17 @@ DOM_SRCDIRS = \
   dom/battery \
   dom/file \
   dom/power \
   dom/media \
   dom/network/src \
   dom/settings \
   dom/sms/src \
   dom/contacts \
+  dom/alarm \
   dom/src/events \
   dom/src/storage \
   dom/src/offline \
   dom/src/geolocation \
   dom/src/notification \
   dom/workers \
   content/xbl/src \
   content/xul/document/src \

--- a/layout/build/Makefile.in
+++ b/layout/build/Makefile.in
@@ -57,16 +57,17 @@ SHARED_LIBRARY_LIBS = \
 	$(DEPTH)/content/xslt/src/xpath/$(LIB_PREFIX)txxpath_s.$(LIB_SUFFIX) \
 	$(DEPTH)/content/xslt/src/xslt/$(LIB_PREFIX)txxslt_s.$(LIB_SUFFIX) \
 	$(DEPTH)/content/xbl/src/$(LIB_PREFIX)gkconxbl_s.$(LIB_SUFFIX) \
 	$(DEPTH)/content/xul/document/src/$(LIB_PREFIX)gkconxuldoc_s.$(LIB_SUFFIX) \
 	$(DEPTH)/view/src/$(LIB_PREFIX)gkview_s.$(LIB_SUFFIX) \
 	$(DEPTH)/dom/base/$(LIB_PREFIX)jsdombase_s.$(LIB_SUFFIX) \
 	$(DEPTH)/dom/battery/$(LIB_PREFIX)dom_battery_s.$(LIB_SUFFIX) \
 	$(DEPTH)/dom/contacts/$(LIB_PREFIX)jsdomcontacts_s.$(LIB_SUFFIX) \
+	$(DEPTH)/dom/alarm/$(LIB_PREFIX)domalarm_s.$(LIB_SUFFIX) \
 	$(DEPTH)/dom/devicestorage/$(LIB_PREFIX)domdevicestorage_s.$(LIB_SUFFIX) \
 	$(DEPTH)/dom/file/$(LIB_PREFIX)domfile_s.$(LIB_SUFFIX) \
 	$(DEPTH)/dom/power/$(LIB_PREFIX)dom_power_s.$(LIB_SUFFIX) \
 	$(DEPTH)/dom/settings/$(LIB_PREFIX)jsdomsettings_s.$(LIB_SUFFIX) \
 	$(DEPTH)/dom/network/src/$(LIB_PREFIX)dom_network_s.$(LIB_SUFFIX) \
 	$(DEPTH)/dom/media/$(LIB_PREFIX)dom_media_s.$(LIB_SUFFIX) \
 	$(DEPTH)/dom/sms/src/$(LIB_PREFIX)dom_sms_s.$(LIB_SUFFIX) \
 	$(DEPTH)/dom/src/events/$(LIB_PREFIX)jsdomevents_s.$(LIB_SUFFIX) \

--- a/modules/libpref/src/init/all.js
+++ b/modules/libpref/src/init/all.js
@@ -3572,16 +3572,19 @@ pref("dom.battery.enabled", true);
 // WebSMS
 pref("dom.sms.enabled", false);
 pref("dom.sms.whitelist", "");
 
 // WebContacts
 pref("dom.mozContacts.enabled", false);
 pref("dom.mozContacts.whitelist", "");
 
+// WebAlarms
+pref("dom.mozAlarms.enabled", false);
+
 // WebSettings
 pref("dom.mozSettings.enabled", false);
 
 // enable JS dump() function.
 pref("browser.dom.window.dump.enabled", false);
 
 // SPS Profiler
 pref("profiler.enabled", false);

--- a/toolkit/toolkit-makefiles.sh
+++ b/toolkit/toolkit-makefiles.sh
@@ -30,16 +30,17 @@ MAKEFILES_dom="
   dom/interfaces/sidebar/Makefile
   dom/interfaces/storage/Makefile
   dom/interfaces/stylesheets/Makefile
   dom/interfaces/svg/Makefile
   dom/interfaces/traversal/Makefile
   dom/interfaces/xbl/Makefile
   dom/interfaces/xpath/Makefile
   dom/interfaces/xul/Makefile
+  dom/alarm/Makefile
   dom/base/Makefile
   dom/battery/Makefile
   dom/file/Makefile
   dom/indexedDB/Makefile
   dom/ipc/Makefile
   dom/locales/Makefile
   dom/messages/Makefile
   dom/messages/interfaces/Makefile
@@ -704,16 +705,17 @@ if [ "$ENABLE_TESTS" ]; then
     content/xml/document/test/Makefile
     content/xslt/tests/buster/Makefile
     content/xslt/tests/mochitest/Makefile
     content/xul/content/test/Makefile
     content/xul/document/test/Makefile
     docshell/test/Makefile
     docshell/test/chrome/Makefile
     docshell/test/navigation/Makefile
+    dom/alarm/test/Makefile
     dom/battery/test/Makefile
     dom/indexedDB/test/Makefile
     dom/indexedDB/test/unit/Makefile
     dom/network/tests/Makefile
     dom/plugins/test/Makefile
     dom/plugins/test/testplugin/Makefile
     dom/power/test/Makefile
     dom/sms/tests/Makefile