diff --git a/frontend/js/forms.js b/frontend/js/forms.js
index 67b14b32..db1a3f83 100644
--- a/frontend/js/forms.js
+++ b/frontend/js/forms.js
@@ -2,10 +2,10 @@
  * Sets all checkboxes to the wanted state
  *
  * @param {string} id Id of the element containing all the checkboxes
- * @param {bool} checked True if the checkboxes should be checked
+ * @param {boolean} checked True if the checkboxes should be checked
  */
 global.checkAll = (id, checked) => {
-    $("#" + id + " input[type='checkbox']").each(function () {
+    $('#' + id + ' input[type="checkbox"]').each(function () {
         this.checked = checked;
     });
 }
@@ -17,7 +17,7 @@ global.checkAll = (id, checked) => {
  * @param {list} shifts_list A list of numbers
  */
 global.checkOwnTypes = (id, shifts_list) => {
-    $("#" + id + " input[type='checkbox']").each(function () {
+    $('#' + id + ' input[type="checkbox"]').each(function () {
         this.checked = $.inArray(parseInt(this.value), shifts_list) != -1;
     });
 }
@@ -26,14 +26,14 @@ global.checkOwnTypes = (id, shifts_list) => {
  * @param {moment} date
  */
 global.formatDay = (date) => {
-    return date.format("YYYY-MM-DD");
+    return date.format('YYYY-MM-DD');
 }
 
 /**
  * @param {moment} date
  */
 global.formatTime = (date) => {
-    return date.format("HH:mm");
+    return date.format('HH:mm');
 }
 
 /**
@@ -41,7 +41,7 @@ global.formatTime = (date) => {
  * @param {moment} to
  */
 global.setInput = (from, to) => {
-    var fromDay = $("#start_day"), fromTime = $("#start_time"), toDay = $("#end_day"), toTime = $("#end_time");
+    var fromDay = $('#start_day'), fromTime = $('#start_time'), toDay = $('#end_day'), toTime = $('#end_time');
 
     fromDay.val(formatDay(from));
     fromTime.val(formatTime(from));
@@ -56,7 +56,7 @@ global.setDay = (days) => {
     var from = moment();
     from.hours(0).minutes(0).seconds(0);
 
-    from.add(days, "d");
+    from.add(days, 'd');
 
     var to = from.clone();
     to.hours(23).minutes(59);
@@ -70,7 +70,7 @@ global.setHours = (hours) => {
     var from = moment();
     var to = from.clone();
 
-    to.add(hours, "h");
+    to.add(hours, 'h');
     if (to < from) {
         setInput(to, from);
         return;
@@ -83,12 +83,12 @@ $(function () {
     /**
      * Disable every submit button after clicking (to prevent double-clicking)
      */
-    $("form").submit(function (ev) {
-        $("input[type='submit']").prop("readonly", true).addClass("disabled");
+    $('form').submit(function (ev) {
+        $('input[type="submit"]').prop('readonly', true).addClass('disabled');
         return true;
     });
 
-    $(".dropdown-menu").css("max-height", function () {
-        return ($(window).height() - 50) + "px";
-    }).css("overflow-y", "scroll");
+    $('.dropdown-menu').css('max-height', function () {
+        return ($(window).height() - 50) + 'px';
+    }).css('overflow-y', 'scroll');
 });
diff --git a/frontend/js/moment-countdown.js b/frontend/js/moment-countdown.js
index feb7b604..f5effbc0 100644
--- a/frontend/js/moment-countdown.js
+++ b/frontend/js/moment-countdown.js
@@ -1,18 +1,18 @@
 /*
  * Initialize all moment countdowns on the page. A moment countdown has the
- * class "moment-countdown" and the attribute "data-timestamp" which defines the
+ * class 'moment-countdown' and the attribute 'data-timestamp' which defines the
  * countdown's time goal.
  */
 $(document).ready(function () {
-    if (typeof moment !== "undefined") {
-        $.each($(".moment-countdown"), function (i, e) {
+    if (typeof moment !== 'undefined') {
+        $.each($('.moment-countdown'), function (i, e) {
             var span = $(e);
             var text = span.html();
             /* global moment */
-            var timestamp = moment(parseInt(span.attr("data-timestamp") * 1000));
-            span.html(text.replace("%c", timestamp.fromNow()));
+            var timestamp = moment(parseInt(span.attr('data-timestamp') * 1000));
+            span.html(text.replace('%c', timestamp.fromNow()));
             setInterval(function () {
-                span.html(text.replace("%c", timestamp.fromNow()));
+                span.html(text.replace('%c', timestamp.fromNow()));
             }, 1000);
         });
     }
diff --git a/frontend/js/sticky-headers.js b/frontend/js/sticky-headers.js
index 6e6a75e2..c664387c 100644
--- a/frontend/js/sticky-headers.js
+++ b/frontend/js/sticky-headers.js
@@ -2,29 +2,29 @@
  * Enables the fixed headers and time lane for the shift-calendar and datatables
  */
 $(document).ready(function () {
-    if ($(".shift-calendar").length) {
-        var timeLanes = $(".shift-calendar .time");
-        var headers = $(".shift-calendar .header");
-        var topReference = $(".container-fluid .row");
+    if ($('.shift-calendar').length) {
+        var timeLanes = $('.shift-calendar .time');
+        var headers = $('.shift-calendar .header');
+        var topReference = $('.container-fluid .row');
         timeLanes.css({
-            "position": "relative",
-            "z-index": 999
+            'position': 'relative',
+            'z-index': 999
         });
         headers.css({
-            "position": "relative",
-            "z-index": 900
+            'position': 'relative',
+            'z-index': 900
         });
         $(window).scroll(
             function () {
                 var top = headers.parent().offset().top;
                 var left = 15;
                 timeLanes.css({
-                    "left": Math.max(0, $(window).scrollLeft() - left) + "px"
+                    'left': Math.max(0, $(window).scrollLeft() - left) + 'px'
                 });
                 headers.css({
-                    "top": Math.max(0, $(window).scrollTop() - top
+                    'top': Math.max(0, $(window).scrollTop() - top
                         + topReference.offset().top)
-                    + "px"
+                        + 'px'
                 });
             });
     }
diff --git a/frontend/js/vendor.js b/frontend/js/vendor.js
index 467fa2ac..dd6b66b3 100644
--- a/frontend/js/vendor.js
+++ b/frontend/js/vendor.js
@@ -12,5 +12,5 @@ require('./sticky-headers');
 require('./moment-countdown');
 
 $(function () {
-    moment.locale("%locale%");
+    moment.locale($('html').attr('lang'));
 });
diff --git a/includes/helper/graph_helper.php b/includes/helper/graph_helper.php
index 12c7df6c..f49ab635 100644
--- a/includes/helper/graph_helper.php
+++ b/includes/helper/graph_helper.php
@@ -33,7 +33,7 @@ function bargraph($dom_id, $key, $row_names, $colors, $data)
     return '<canvas id="' . $dom_id . '" style="width: 100%; height: 300px;"></canvas>
       <script type="text/javascript">
       $(function(){
-        var ctx = $("#' . $dom_id . '").get(0).getContext("2d");
+        var ctx = $(\'#' . $dom_id . '\').get(0).getContext(\'2d\');
         var chart = new Chart(ctx).Bar(' . json_encode([
             'labels'   => $labels,
             'datasets' => $datasets
diff --git a/includes/sys_form.php b/includes/sys_form.php
index 05df4c15..797ba52e 100644
--- a/includes/sys_form.php
+++ b/includes/sys_form.php
@@ -38,12 +38,12 @@ function form_spinner($name, $label, $value)
         </div>
       </div>
       <script type="text/javascript">
-        $("#spinner-' . $name . '-down").click(function() {
-          var spinner = $("#spinner-' . $name . '");
+        $(\'#spinner-' . $name . '-down\').click(function() {
+          var spinner = $(\'#spinner-' . $name . '\');
           spinner.val(parseInt(spinner.val()) - 1);
         });
-        $("#spinner-' . $name . '-up").click(function() {
-          var spinner = $("#spinner-' . $name . '");
+        $(\'#spinner-' . $name . '-up\').click(function() {
+          var spinner = $(\'#spinner-' . $name . '\');
           spinner.val(parseInt(spinner.val()) + 1);
         });
       </script>
@@ -73,13 +73,13 @@ function form_date($name, $label, $value, $start_date = '', $end_date = '')
     </div>
     <script type="text/javascript">
 			$(function(){
-        $("#' . $dom_id . '").datepicker({
-				  language: "' . locale_short() . '",
-          todayBtn: "linked",
-          format: "yyyy-mm-dd",
-          startDate: "' . $start_date . '",
-          endDate: "' . $end_date . '",
-          orientation: "bottom"
+        $(\'#' . $dom_id . '\').datepicker({
+				  language: \'' . locale_short() . '\',
+          todayBtn: \'linked\',
+          format: \'yyyy-mm-dd\',
+          startDate: \'' . $start_date . '\',
+          endDate: \'' . $end_date . '\',
+          orientation: \'bottom\'
 			  });
       });
     </script>
diff --git a/includes/sys_template.php b/includes/sys_template.php
index a988ca7c..986270b5 100644
--- a/includes/sys_template.php
+++ b/includes/sys_template.php
@@ -231,12 +231,12 @@ function toolbar_popover($glyphicon, $label, $content, $class = '')
         . ' <span class="caret"></span></a>
           <script type="text/javascript">
           $(function(){
-              $("#' . $dom_id . '").popover({
-                  trigger: "focus",
+              $(\'#' . $dom_id . '\').popover({
+                  trigger: \'focus\',
                   html: true,
-                  content: "' . addslashes(join('', $content)) . '",
-                  placement: "bottom",
-                  container: "#navbar-collapse-1"
+                  content: \'' . addslashes(join('', $content)) . '\',
+                  placement: \'bottom\',
+                  container: \'#navbar-collapse-1\'
               })
           });
           </script></li>';
diff --git a/includes/view/UserDriverLicenses_view.php b/includes/view/UserDriverLicenses_view.php
index b92f5f07..be21ca53 100644
--- a/includes/view/UserDriverLicenses_view.php
+++ b/includes/view/UserDriverLicenses_view.php
@@ -53,18 +53,18 @@ function UserDriverLicense_edit_view($user_source, $wants_to_drive, $user_driver
         ]),
         '<script type="text/javascript">
         $(function() {
-          var checkbox = $("#wants_to_drive");
-          if(checkbox.is(":checked"))
-            $("#driving_license").show();
+          var checkbox = $(\'#wants_to_drive\');
+          if(checkbox.is(\':checked\'))
+            $(\'#driving_license\').show();
           else
-            $("#driving_license").hide();
+            $(\'#driving_license\').hide();
 
           checkbox.click(
             function() {
-              if($("#wants_to_drive").is(":checked"))
-                $("#driving_license").show();
+              if($(\'#wants_to_drive\').is(\':checked\'))
+                $(\'#driving_license\').show();
               else
-                $("#driving_license").hide();
+                $(\'#driving_license\').hide();
             }
           );
         });
diff --git a/public/index.php b/public/index.php
index adf22e71..0528f531 100755
--- a/public/index.php
+++ b/public/index.php
@@ -247,6 +247,6 @@ echo view(__DIR__ . '/../templates/layout.html', [
     'header_toolbar' => header_toolbar(),
     'faq_url'        => config('faq_url'),
     'contact_email'  => config('contact_email'),
-    'locale'         => locale(),
+    'locale'         => locale_short(),
     'event_info'     => EventConfig_info($event_config) . ' <br />'
 ]);
diff --git a/templates/layout.html b/templates/layout.html
index 3ec6decc..c87ff3d4 100644
--- a/templates/layout.html
+++ b/templates/layout.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html>
+<html lang="%locale%">
 <head>
     <title>%title% - Engelsystem</title>
     <meta charset="UTF-8"/>