diff --git a/scripts/langindex.json b/scripts/langindex.json
index 614f7c5b0..3c3c3e1f9 100644
--- a/scripts/langindex.json
+++ b/scripts/langindex.json
@@ -1792,6 +1792,7 @@
   "core.fileuploader.uploadingperc": "local_moodlemobileapp",
   "core.fileuploader.video": "local_moodlemobileapp",
   "core.filter": "moodle",
+  "core.firstdayofweek": "langconfig",
   "core.folder": "moodle",
   "core.forcepasswordchangenotice": "moodle",
   "core.fulllistofcourses": "moodle",
diff --git a/src/core/constants.ts b/src/core/constants.ts
index 35a26c3b0..a5d6ef786 100644
--- a/src/core/constants.ts
+++ b/src/core/constants.ts
@@ -153,6 +153,9 @@ export class CoreConstants {
     static readonly MOD_ARCHETYPE_ASSIGNMENT = 2; // Assignment module archetype.
     static readonly MOD_ARCHETYPE_SYSTEM = 3; // System (not user-addable) module archetype.
 
+    // Other constants.
+    static readonly CALENDAR_DEFAULT_STARTING_WEEKDAY = 1;
+
     // Config & environment constants.
     static readonly CONFIG = { ...envJson.config } as unknown as EnvironmentConfig; // Data parsed from config.json files.
     static readonly BUILD = envJson.build as unknown as EnvironmentBuild; // Build info.
diff --git a/src/core/directives/datetime.ts b/src/core/directives/datetime.ts
new file mode 100644
index 000000000..f2d1ca1f3
--- /dev/null
+++ b/src/core/directives/datetime.ts
@@ -0,0 +1,62 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { Directive, OnInit } from '@angular/core';
+import { CoreLang } from '@services/lang';
+import { CoreUser } from '@features/user/services/user';
+import { IonDatetime } from '@ionic/angular';
+
+/**
+ * Directive to automatically add language and starting week day to ion-datetime.
+ */
+@Directive({
+    selector: 'ion-datetime',
+})
+export class CoreIonDatetimeDirective implements OnInit {
+
+    constructor(protected datetime: IonDatetime) {}
+
+    /**
+     * @inheritdoc
+     */
+    ngOnInit(): void {
+        this.setLanguage();
+        this.setStartingWeekDay();
+    }
+
+    /**
+     * Set language to use.
+     */
+    protected async setLanguage(): Promise<void> {
+        if (this.datetime.locale) {
+            return;
+        }
+
+        const language = await CoreLang.getCurrentLanguage();
+        this.datetime.locale = language;
+    }
+
+    /**
+     * Set starting week day.
+     */
+    protected async setStartingWeekDay(): Promise<void> {
+        if (this.datetime.firstDayOfWeek || this.datetime.firstDayOfWeek === 0) {
+            return;
+        }
+
+        const startingDay = await CoreUser.getStartingWeekDay();
+        this.datetime.firstDayOfWeek = startingDay;
+    }
+
+}
diff --git a/src/core/directives/directives.module.ts b/src/core/directives/directives.module.ts
index d004ce3cd..6225f56a1 100644
--- a/src/core/directives/directives.module.ts
+++ b/src/core/directives/directives.module.ts
@@ -34,6 +34,7 @@ import { CoreCollapsibleFooterDirective } from './collapsible-footer';
 import { CoreContentDirective } from './content';
 import { CoreUpdateNonReactiveAttributesDirective } from './update-non-reactive-attributes';
 import { CoreUserTourDirective } from './user-tour';
+import { CoreIonDatetimeDirective } from './datetime';
 
 @NgModule({
     declarations: [
@@ -57,6 +58,7 @@ import { CoreUserTourDirective } from './user-tour';
         CoreContentDirective,
         CoreUpdateNonReactiveAttributesDirective,
         CoreUserTourDirective,
+        CoreIonDatetimeDirective,
     ],
     exports: [
         CoreAutoFocusDirective,
@@ -79,6 +81,7 @@ import { CoreUserTourDirective } from './user-tour';
         CoreContentDirective,
         CoreUpdateNonReactiveAttributesDirective,
         CoreUserTourDirective,
+        CoreIonDatetimeDirective,
     ],
 })
 export class CoreDirectivesModule {}
diff --git a/src/core/features/user/services/user.ts b/src/core/features/user/services/user.ts
index a577bd333..d603f6433 100644
--- a/src/core/features/user/services/user.ts
+++ b/src/core/features/user/services/user.ts
@@ -29,6 +29,7 @@ import { USERS_TABLE_NAME, CoreUserDBRecord } from './database/user';
 import { CoreUserHelper } from './user-helper';
 import { CoreUrlUtils } from '@services/utils/url';
 import { CoreSiteWSPreSets } from '@classes/sites/authenticated-site';
+import { CoreConstants } from '@/core/constants';
 
 const ROOT_CACHE_KEY = 'mmUser:';
 
@@ -285,6 +286,24 @@ export class CoreUserProvider {
         }
     }
 
+    /**
+     * Get the starting week day based on the user preference.
+     *
+     * @returns Starting week day.
+     */
+    async getStartingWeekDay(): Promise<number> {
+        const preference = await CoreUtils.ignoreErrors(this.getUserPreference('calendar_startwday'));
+
+        if (preference && !isNaN(Number(preference))) {
+            return Number(preference);
+        }
+
+        const defaultValue = Number(CoreSites.getCurrentSite()?.getStoredConfig('calendar_startwday') ??
+            Translate.instant('core.firstdayofweek'));
+
+        return !isNaN(defaultValue) ? defaultValue % 7 : CoreConstants.CALENDAR_DEFAULT_STARTING_WEEKDAY;
+    }
+
     /**
      * Get cache key for a user WS call.
      *
diff --git a/src/core/lang.json b/src/core/lang.json
index f917f2929..ca0e0007a 100644
--- a/src/core/lang.json
+++ b/src/core/lang.json
@@ -131,6 +131,7 @@
     "filenameexist": "File name already exists: {{$a}}",
     "filenotfound": "File not found, sorry.",
     "filter": "Filter",
+    "firstdayofweek": "1",
     "folder": "Folder",
     "forcepasswordchangenotice": "You must change your password to proceed.",
     "fulllistofcourses": "All courses",