diff --git a/assets/js/utils/calendar_default_view.js b/assets/js/utils/calendar_default_view.js
index 216ce69e..cbe5738b 100755
--- a/assets/js/utils/calendar_default_view.js
+++ b/assets/js/utils/calendar_default_view.js
@@ -81,38 +81,37 @@ App.Utils.CalendarDefaultView = (function () {
                 const workingPlanException = lastFocusedEventData.data.workingPlanException;
                 const provider = lastFocusedEventData.data.provider;
 
-                App.Components.WorkingPlanExceptionsModal.edit(date, workingPlanException).done(function (
-                    date,
-                    workingPlanException
-                ) {
-                    const successCallback = function () {
-                        App.Layouts.Backend.displayNotification(App.Lang.working_plan_exception_saved);
+                App.Components.WorkingPlanExceptionsModal.edit(date, workingPlanException).done(
+                    (date, workingPlanException) => {
+                        const successCallback = () => {
+                            App.Layouts.Backend.displayNotification(App.Lang.working_plan_exception_saved);
 
-                        const workingPlanExceptions = JSON.parse(provider.settings.working_plan_exceptions) || {};
+                            const workingPlanExceptions = JSON.parse(provider.settings.working_plan_exceptions) || {};
 
-                        workingPlanExceptions[date] = workingPlanException;
+                            workingPlanExceptions[date] = workingPlanException;
 
-                        for (const index in App.Vars.available_providers) {
-                            const availableProvider = App.Vars.available_providers[index];
+                            for (const index in App.Vars.available_providers) {
+                                const availableProvider = App.Vars.available_providers[index];
 
-                            if (Number(availableProvider.id) === Number(provider.id)) {
-                                availableProvider.settings.working_plan_exceptions =
-                                    JSON.stringify(workingPlanExceptions);
-                                break;
+                                if (Number(availableProvider.id) === Number(provider.id)) {
+                                    availableProvider.settings.working_plan_exceptions =
+                                        JSON.stringify(workingPlanExceptions);
+                                    break;
+                                }
                             }
-                        }
 
-                        $selectFilterItem.trigger('change'); // Update the calendar.
-                    };
+                            $selectFilterItem.trigger('change'); // Update the calendar.
+                        };
 
-                    App.Http.Calendar.saveWorkingPlanException(
-                        date,
-                        workingPlanException,
-                        provider.id,
-                        successCallback,
-                        null
-                    );
-                });
+                        App.Http.Calendar.saveWorkingPlanException(
+                            date,
+                            workingPlanException,
+                            provider.id,
+                            successCallback,
+                            null
+                        );
+                    }
+                );
             } else if (!lastFocusedEventData.data.is_unavailable) {
                 const appointment = lastFocusedEventData.data;
 
@@ -224,7 +223,7 @@ App.Utils.CalendarDefaultView = (function () {
                     },
                     {
                         text: 'OK',
-                        click: function () {
+                        click: () => {
                             url = App.Utils.Url.siteUrl('calendar/ajax_delete_appointment');
 
                             data = {
@@ -294,9 +293,9 @@ App.Utils.CalendarDefaultView = (function () {
 
                 const providerId = $selectFilterItem.val();
 
-                const provider = App.Vars.available_providers.find(function (availableProvider) {
-                    return Number(availableProvider.id) === Number(providerId);
-                });
+                const provider = App.Vars.available_providers.find(
+                    (availableProvider) => Number(availableProvider.id) === Number(providerId)
+                );
 
                 if (provider && provider.timezone) {
                     $('.provider-timezone').text(App.Vars.timezones[provider.timezone]);
@@ -1629,7 +1628,7 @@ App.Utils.CalendarDefaultView = (function () {
             $('<optgroup label=""/>', {
                 'label': App.Lang.providers,
                 'type': 'providers-group',
-                'html': App.Vars.available_providers.map(function (availableProvider) {
+                'html': App.Vars.available_providers.map((availableProvider) => {
                     const hasGoogleSync = availableProvider.settings.google_sync === '1' ? 'true' : 'false';
 
                     return $('<option/>', {
diff --git a/assets/js/utils/calendar_google_sync.js b/assets/js/utils/calendar_google_sync.js
index 3d835751..fdcc7502 100644
--- a/assets/js/utils/calendar_google_sync.js
+++ b/assets/js/utils/calendar_google_sync.js
@@ -18,9 +18,9 @@
  */
 App.Utils.CalendarGoogleSync = (function () {
     /**
-     * Bind the event handlers.
+     * Add the utility event listeners.
      */
-    function bindEventHandlers() {
+    function addEventListeners() {
         /**
          * Event: Enable - Disable Synchronization Button "Click"
          *
@@ -182,7 +182,7 @@ App.Utils.CalendarGoogleSync = (function () {
      * Initialize the module.
      */
     function initialize() {
-        bindEventHandlers();
+        addEventListeners();
     }
 
     document.addEventListener('DOMContentLoaded', initialize);
diff --git a/assets/js/utils/calendar_table_view.js b/assets/js/utils/calendar_table_view.js
index 9babad99..870d1c13 100755
--- a/assets/js/utils/calendar_table_view.js
+++ b/assets/js/utils/calendar_table_view.js
@@ -22,9 +22,9 @@ App.Utils.CalendarTableView = (function () {
     let lastFocusedEventData;
 
     /**
-     * Bind the event handlers.
+     * Add the utility event listeners.
      */
-    function bindEventHandlers() {
+    function addEventListeners() {
         const $calendarToolbar = $('#calendar-toolbar');
         const $calendar = $('#calendar');
 
@@ -82,7 +82,7 @@ App.Utils.CalendarTableView = (function () {
                             .find('.date-column-title')
                             .text(App.Utils.Date.format(date, App.Vars.date_format, App.Vars.time_format));
 
-                        $dateColumn.find('.provider-column').each(function (index, providerColumn) {
+                        $dateColumn.find('.provider-column').each((index, providerColumn) => {
                             const $providerColumn = $(providerColumn);
                             const provider = $providerColumn.data('provider');
 
@@ -277,7 +277,7 @@ App.Utils.CalendarTableView = (function () {
                 const buttons = [
                     {
                         text: App.Lang.cancel,
-                        click: function () {
+                        click: () => {
                             $('#message-box').dialog('close');
                         }
                     },
@@ -444,9 +444,7 @@ App.Utils.CalendarTableView = (function () {
         $filterProvider.select2();
 
         const services = GlobalVariables.availableServices.filter((service) => {
-            const provider = providers.find(function (provider) {
-                return provider.services.indexOf(service.id) !== -1;
-            });
+            const provider = providers.find((provider) => provider.services.indexOf(service.id) !== -1);
 
             return App.Vars.role_slug === App.Layouts.Backend.DB_SLUG_ADMIN || provider;
         });
@@ -689,8 +687,8 @@ App.Utils.CalendarTableView = (function () {
                 throw new Error('Invalid time format setting provided!' + GlobalVariables.timeFormat);
         }
 
-        const firstWeekday = GlobalVariables.firstWeekday;
-        const firstWeekdayNumber = GeneralFunctions.getWeekDayId(firstWeekday);
+        const firstWeekday = App.Vars.first_weekday;
+        const firstWeekdayNumber = App.Utils.Date.getWeekdayId(firstWeekday);
 
         $wrapper.fullCalendar({
             defaultView: 'agendaDay',
@@ -1517,7 +1515,7 @@ App.Utils.CalendarTableView = (function () {
                 .add({days: delta.days(), hours: delta.hours(), minutes: delta.minutes()})
                 .format('YYYY-MM-DD HH:mm:ss');
 
-            const appointment = GeneralFunctions.clone(event.data);
+            const appointment = {...event.data};
 
             // Must delete the following because only appointment data should be provided to the AJAX call.
             delete appointment.customer;
@@ -1631,7 +1629,7 @@ App.Utils.CalendarTableView = (function () {
 
         if (event.data.is_unavailable === '0') {
             // Prepare appointment data.
-            const appointment = GeneralFunctions.clone(event.data);
+            const appointment = {...event.data};
 
             // Must delete the following because only appointment data should be provided to the ajax call.
             delete appointment.customer;
@@ -1671,7 +1669,7 @@ App.Utils.CalendarTableView = (function () {
                         appointment_data: JSON.stringify(appointment)
                     };
 
-                    $.post(url, data).done(function () {
+                    $.post(url, data).done(() => {
                         $('#notification').hide('blind');
                     });
 
@@ -1766,7 +1764,7 @@ App.Utils.CalendarTableView = (function () {
 
         let width = 0;
 
-        $dateColumn.each(function (index, dateColumn) {
+        $dateColumn.each((index, dateColumn) => {
             width += $(dateColumn).outerWidth();
         });
 
@@ -1823,7 +1821,7 @@ App.Utils.CalendarTableView = (function () {
 
         $('#insert-working-plan-exception').hide();
 
-        bindEventHandlers();
+        addEventListeners();
 
         // Hide Google Calendar Sync buttons cause they can not be used within this view.
         $('#enable-sync, #google-sync').hide();