--- a/.eslintignore
+++ b/.eslintignore
@@ -27,16 +27,15 @@ ldap/**
 mail/**
 mailnews/**
 suite/**
 
 # calendar/ exclusions
 
 # prefs files
 calendar/lightning/content/lightning.js
-calendar/locales/en-US/lightning-l10n.js
 
 # third party library
 calendar/base/modules/ical.js
 
 # preprocessed files
 calendar/base/content/dialogs/calendar-migration-dialog.js
 calendar/base/content/calendar-dnd-listener.js

deleted file mode 100644
--- a/calendar/locales/en-US/lightning-l10n.js
+++ /dev/null
@@ -1,21 +0,0 @@
-# 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/.
-
-#filter substitution
-
-# the default day to start the week on
-#0=Sunday 1=Monday 2=Tuesday 3=Wednesday 4=Thursday 5=Friday 6=Saturday
-pref("calendar.week.start", 0);
-
-# default days off (not in work week)
-pref("calendar.week.d0sundaysoff", true);
-pref("calendar.week.d1mondaysoff", false);
-pref("calendar.week.d2tuesdaysoff", false);
-pref("calendar.week.d3wednesdaysoff", false);
-pref("calendar.week.d4thursdaysoff", false);
-pref("calendar.week.d5fridaysoff", false);
-pref("calendar.week.d6saturdaysoff", true);
-
-# categories
-pref("calendar.categories.names", "Anniversary,Birthday,Business,Calls,Clients,Competition,Customer,Favorites,Follow up,Gifts,Holidays,Ideas,Issues,Meeting,Miscellaneous,Personal,Projects,Public Holiday,Status,Suppliers,Travel,Vacation");

--- a/calendar/locales/moz.build
+++ b/calendar/locales/moz.build
@@ -1,10 +1,6 @@
 # vim: set filetype=python:
 # 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/.
 
 JAR_MANIFESTS += ['jar.mn']
-
-LOCALIZED_PP_FILES.defaults.preferences += [
-    'en-US/lightning-l10n.js'
-]