diff --git a/addons/calendar/static/tests/helpers/mock_server/models/res_users.js b/addons/calendar/static/tests/helpers/mock_server/models/res_users.js
index 163f72ff321..bc35ddd3120 100644
--- a/addons/calendar/static/tests/helpers/mock_server/models/res_users.js
+++ b/addons/calendar/static/tests/helpers/mock_server/models/res_users.js
@@ -1,12 +1,12 @@
 /** @odoo-module **/
 
 // ensure mail override is applied first.
-import '@mail/../tests/helpers/mock_server/models/res_users';
+import "@mail/../tests/helpers/mock_server/models/res_users";
 
 import { patch } from "@web/core/utils/patch";
-import { MockServer } from '@web/../tests/helpers/mock_server';
-
-import { datetime_to_str } from '@web/legacy/js/core/time';
+import { serializeDateTime } from "@web/core/l10n/dates";
+import { MockServer } from "@web/../tests/helpers/mock_server";
+const { DateTime } = luxon;
 
 patch(MockServer.prototype, {
     /**
@@ -15,23 +15,35 @@ patch(MockServer.prototype, {
      * @private
      */
     _mockResUsers_SystrayGetCalendarEventDomain() {
-        const startDate = new Date();
-        startDate.setUTCHours(0, 0, 0, 0);
-        const endDate = new Date();
-        endDate.setUTCHours(23, 59, 59, 999);
-        const currentPartnerAttendeeIds = this.pyEnv['calendar.attendee'].search([['partner_id', '=', this.pyEnv.currentPartnerId], ['state', '!=', 'declined']]);
+        const startDate = DateTime.fromObject({
+            hours: 0,
+            minutes: 0,
+            seconds: 0,
+            milliseconds: 0,
+        });
+        const endDate = DateTime.fromObject({
+            hours: 23,
+            minutes: 59,
+            seconds: 59,
+            milliseconds: 999,
+        });
+
+        const currentPartnerAttendeeIds = this.pyEnv["calendar.attendee"].search([
+            ["partner_id", "=", this.pyEnv.currentPartnerId],
+            ["state", "!=", "declined"],
+        ]);
         return [
-            '&',
-                '|',
-                    '&',
-                        '|',
-                            ['start', '>=', datetime_to_str(startDate)],
-                            ['stop', '>=', datetime_to_str(startDate)],
-                        ['start', '<=', datetime_to_str(endDate)],
-                    '&',
-                        ['allday', '=', true],
-                        ['start_date', '=', datetime_to_str(startDate)],
-                ['attendee_ids', 'in', currentPartnerAttendeeIds],
+            "&",
+            "|",
+            "&",
+            "|",
+            ["start", ">=", serializeDateTime(startDate)],
+            ["stop", ">=", serializeDateTime(startDate)],
+            ["start", "<=", serializeDateTime(endDate)],
+            "&",
+            ["allday", "=", true],
+            ["start_date", "=", serializeDateTime(startDate)],
+            ["attendee_ids", "in", currentPartnerAttendeeIds],
         ];
     },
 
@@ -42,20 +54,20 @@ patch(MockServer.prototype, {
      */
     _mockResUsersSystrayGetActivities() {
         const activities = super._mockResUsersSystrayGetActivities(...arguments);
-        const meetingsLines = this.pyEnv['calendar.event'].searchRead(
+        const meetingsLines = this.pyEnv["calendar.event"].searchRead(
             this._mockResUsers_SystrayGetCalendarEventDomain(),
             {
-                fields: ['id', 'start', 'name', 'allday'],
-                order: 'start',
+                fields: ["id", "start", "name", "allday"],
+                order: "start",
             }
-        )
+        );
         if (meetingsLines.length) {
             activities.unshift({
-                id: 'calendar.event', // for simplicity
+                id: "calendar.event", // for simplicity
                 meetings: meetingsLines,
-                model: 'calendar.event',
-                name: 'Today\'s Meetings',
-                type: 'meeting',
+                model: "calendar.event",
+                name: "Today's Meetings",
+                type: "meeting",
             });
         }
         return activities;
diff --git a/addons/mail/static/tests/activity/activity_tests.js b/addons/mail/static/tests/activity/activity_tests.js
index 29a8804077f..68968dc3972 100644
--- a/addons/mail/static/tests/activity/activity_tests.js
+++ b/addons/mail/static/tests/activity/activity_tests.js
@@ -4,7 +4,7 @@ import { startServer } from "@bus/../tests/helpers/mock_python_environment";
 
 import { start } from "@mail/../tests/helpers/test_utils";
 
-import { date_to_str } from "@web/legacy/js/core/time";
+import { serializeDate, today } from "@web/core/l10n/dates";
 import {
     mockTimeout,
     patchDate,
@@ -106,13 +106,10 @@ QUnit.test("activity with note layout", async () => {
 
 QUnit.test("activity info layout when planned after tomorrow", async () => {
     patchDate(2023, 0, 11, 12, 0, 0);
-    const today = new Date();
-    const fiveDaysFromNow = new Date();
-    fiveDaysFromNow.setDate(today.getDate() + 5);
     const pyEnv = await startServer();
     const partnerId = pyEnv["res.partner"].create({});
     pyEnv["mail.activity"].create({
-        date_deadline: date_to_str(fiveDaysFromNow),
+        date_deadline: serializeDate(today().plus({ days: 5 })),
         res_id: partnerId,
         res_model: "res.partner",
         state: "planned",
@@ -124,13 +121,11 @@ QUnit.test("activity info layout when planned after tomorrow", async () => {
 
 QUnit.test("activity info layout when planned tomorrow", async () => {
     patchDate(2023, 0, 11, 12, 0, 0);
-    const today = new Date();
-    const tomorrow = new Date();
-    tomorrow.setDate(today.getDate() + 1);
+    const tomorrow = today().plus({ days: 1 });
     const pyEnv = await startServer();
     const partnerId = pyEnv["res.partner"].create({});
     pyEnv["mail.activity"].create({
-        date_deadline: date_to_str(tomorrow),
+        date_deadline: serializeDate(tomorrow),
         res_id: partnerId,
         res_model: "res.partner",
         state: "planned",
@@ -145,7 +140,7 @@ QUnit.test("activity info layout when planned today", async () => {
     const pyEnv = await startServer();
     const partnerId = pyEnv["res.partner"].create({});
     pyEnv["mail.activity"].create({
-        date_deadline: date_to_str(new Date()),
+        date_deadline: serializeDate(today()),
         res_id: partnerId,
         res_model: "res.partner",
         state: "today",
@@ -157,13 +152,11 @@ QUnit.test("activity info layout when planned today", async () => {
 
 QUnit.test("activity info layout when planned yesterday", async () => {
     patchDate(2023, 0, 11, 12, 0, 0);
-    const today = new Date();
-    const yesterday = new Date();
-    yesterday.setDate(today.getDate() - 1);
+    const yesterday = today().plus({ days: -1 });
     const pyEnv = await startServer();
     const partnerId = pyEnv["res.partner"].create({});
     pyEnv["mail.activity"].create({
-        date_deadline: date_to_str(yesterday),
+        date_deadline: serializeDate(yesterday),
         res_id: partnerId,
         res_model: "res.partner",
         state: "overdue",
@@ -175,13 +168,10 @@ QUnit.test("activity info layout when planned yesterday", async () => {
 
 QUnit.test("activity info layout when planned before yesterday", async () => {
     patchDate(2023, 0, 11, 12, 0, 0);
-    const today = new Date();
-    const fiveDaysBeforeNow = new Date();
-    fiveDaysBeforeNow.setDate(today.getDate() - 5);
     const pyEnv = await startServer();
     const partnerId = pyEnv["res.partner"].create({});
     pyEnv["mail.activity"].create({
-        date_deadline: date_to_str(fiveDaysBeforeNow),
+        date_deadline: serializeDate(today().plus({ days: -5 })),
         res_id: partnerId,
         res_model: "res.partner",
         state: "overdue",
@@ -199,13 +189,11 @@ QUnit.test("activity info layout when planned before yesterday", async () => {
 QUnit.skip("activity info layout change at midnight", async () => {
     const mock = mockTimeout();
     patchDate(2023, 11, 7, 23, 59, 59);
-    const today = new Date();
-    const tomorrow = new Date();
-    tomorrow.setDate(today.getDate() + 1);
+    const tomorrow = today().plus({ days: 1 });
     const pyEnv = await startServer();
     const partnerId = pyEnv["res.partner"].create({});
     pyEnv["mail.activity"].create({
-        date_deadline: date_to_str(tomorrow),
+        date_deadline: serializeDate(tomorrow),
         res_id: partnerId,
         res_model: "res.partner",
         state: "planned",
@@ -247,16 +235,14 @@ QUnit.test("activity without summary layout", async () => {
 
 QUnit.test("activity details toggle", async () => {
     patchDate(2023, 0, 11, 12, 0, 0);
-    const today = new Date();
-    const tomorrow = new Date();
-    tomorrow.setDate(today.getDate() + 1);
+    const tomorrow = today().plus({ days: 1 });
     const pyEnv = await startServer();
     const partnerId = pyEnv["res.partner"].create({});
     const userId = pyEnv["res.users"].create({ partner_id: partnerId });
     pyEnv["mail.activity"].create({
-        create_date: date_to_str(today),
+        create_date: serializeDate(today()),
         create_uid: userId,
-        date_deadline: date_to_str(tomorrow),
+        date_deadline: serializeDate(tomorrow),
         res_id: partnerId,
         res_model: "res.partner",
     });
@@ -489,27 +475,24 @@ QUnit.test("activity mark done popover click on discard", async () => {
 
 QUnit.test("Activity are sorted by deadline", async () => {
     patchDate(2023, 0, 11, 12, 0, 0);
-    const today = new Date();
-    const dateBefore = new Date();
-    dateBefore.setDate(today.getDate() - 5);
-    const dateAfter = new Date();
-    dateAfter.setDate(today.getDate() + 4);
+    const dateBefore = today().plus({ days: -5 });
+    const dateAfter = today().plus({ days: 4 });
     const pyEnv = await startServer();
     const partnerId = pyEnv["res.partner"].create({});
     pyEnv["mail.activity"].create({
-        date_deadline: date_to_str(dateAfter),
+        date_deadline: serializeDate(dateAfter),
         res_id: partnerId,
         res_model: "res.partner",
         state: "planned",
     });
     pyEnv["mail.activity"].create({
-        date_deadline: date_to_str(today),
+        date_deadline: serializeDate(today()),
         res_id: partnerId,
         res_model: "res.partner",
         state: "today",
     });
     pyEnv["mail.activity"].create({
-        date_deadline: date_to_str(dateBefore),
+        date_deadline: serializeDate(dateBefore),
         res_id: partnerId,
         res_model: "res.partner",
         state: "overdue",
diff --git a/addons/mail/static/tests/helpers/mock_server/models/discuss_channel.js b/addons/mail/static/tests/helpers/mock_server/models/discuss_channel.js
index 5fc1275a70f..afcff843c6a 100644
--- a/addons/mail/static/tests/helpers/mock_server/models/discuss_channel.js
+++ b/addons/mail/static/tests/helpers/mock_server/models/discuss_channel.js
@@ -3,9 +3,8 @@
 import { patch } from "@web/core/utils/patch";
 import { MockServer } from "@web/../tests/helpers/mock_server";
 
-import { datetime_to_str } from "@web/legacy/js/core/time";
 import { assignDefined } from "@mail/utils/common/misc";
-import { formatDate } from "@web/core/l10n/dates";
+import { formatDate, serializeDateTime, today } from "@web/core/l10n/dates";
 import { Command } from "@mail/../tests/helpers/command";
 const { DateTime } = luxon;
 
@@ -211,7 +210,7 @@ patch(MockServer.prototype, {
             );
             if (memberOfCurrentUser) {
                 this.pyEnv["discuss.channel.member"].write([memberOfCurrentUser.id], {
-                    last_interest_dt: datetime_to_str(new Date()),
+                    last_interest_dt: serializeDateTime(today()),
 
                     is_pinned: true,
                 });
diff --git a/addons/mail/static/tests/helpers/mock_server/models/mail_thread.js b/addons/mail/static/tests/helpers/mock_server/models/mail_thread.js
index 0386c74be52..671efb90e05 100644
--- a/addons/mail/static/tests/helpers/mock_server/models/mail_thread.js
+++ b/addons/mail/static/tests/helpers/mock_server/models/mail_thread.js
@@ -3,7 +3,7 @@
 import { patch } from "@web/core/utils/patch";
 import { MockServer } from "@web/../tests/helpers/mock_server";
 
-import { datetime_to_str } from "@web/legacy/js/core/time";
+import { serializeDateTime, today } from "@web/core/l10n/dates";
 
 patch(MockServer.prototype, {
     async _performRPC(route, args) {
@@ -290,7 +290,7 @@ patch(MockServer.prototype, {
             const channels = this.getRecords("discuss.channel", [["id", "=", message.res_id]]);
             for (const channel of channels) {
                 // notify update of last_interest_dt
-                const now = datetime_to_str(new Date());
+                const now = serializeDateTime(today());
                 const members = this.getRecords("discuss.channel.member", [
                     ["id", "in", channel.channel_member_ids],
                 ]);
diff --git a/addons/mail/static/tests/helpers/mock_server/models/res_users.js b/addons/mail/static/tests/helpers/mock_server/models/res_users.js
index b53f945f6c3..be6e0245141 100644
--- a/addons/mail/static/tests/helpers/mock_server/models/res_users.js
+++ b/addons/mail/static/tests/helpers/mock_server/models/res_users.js
@@ -1,7 +1,7 @@
 /* @odoo-module */
 
 import { patch } from "@web/core/utils/patch";
-import { date_to_str } from "@web/legacy/js/core/time";
+import { today, serializeDate } from "@web/core/l10n/dates";
 import { MockServer } from "@web/../tests/helpers/mock_server";
 
 patch(MockServer.prototype, {
@@ -57,10 +57,10 @@ patch(MockServer.prototype, {
         const activities = this.pyEnv["mail.activity"].searchRead([]);
         const userActivitiesByModelName = {};
         for (const activity of activities) {
-            const today = date_to_str(new Date());
-            if (today === activity["date_deadline"]) {
+            const day = serializeDate(today());
+            if (day === activity["date_deadline"]) {
                 activity["states"] = "today";
-            } else if (today > activity["date_deadline"]) {
+            } else if (day > activity["date_deadline"]) {
                 activity["states"] = "overdue";
             } else {
                 activity["states"] = "planned";
diff --git a/addons/mrp_subcontracting/__manifest__.py b/addons/mrp_subcontracting/__manifest__.py
index 75e2114fb97..994cb9998ff 100644
--- a/addons/mrp_subcontracting/__manifest__.py
+++ b/addons/mrp_subcontracting/__manifest__.py
@@ -97,7 +97,6 @@
             'web/static/src/legacy/js/core/dom.js',
             'web/static/src/legacy/js/core/mixins.js',
             'web/static/src/legacy/js/core/service_mixins.js',
-            'web/static/src/legacy/js/core/time.js',
             'web/static/src/legacy/js/core/widget.js',
             'web/static/src/legacy/js/services/core.js',
 
diff --git a/addons/project/__manifest__.py b/addons/project/__manifest__.py
index 8aa52d9861a..911f8c5ad50 100644
--- a/addons/project/__manifest__.py
+++ b/addons/project/__manifest__.py
@@ -147,7 +147,6 @@
             'web/static/src/legacy/js/core/dom.js',
             'web/static/src/legacy/js/core/mixins.js',
             'web/static/src/legacy/js/core/service_mixins.js',
-            'web/static/src/legacy/js/core/time.js',
             'web/static/src/legacy/js/core/widget.js',
             'web/static/src/legacy/js/services/core.js',
             ('include', 'web._assets_bootstrap_backend'),
diff --git a/addons/project_todo/static/src/web/activity/activity_menu_patch.js b/addons/project_todo/static/src/web/activity/activity_menu_patch.js
index 306f58040a5..23113c2f63d 100644
--- a/addons/project_todo/static/src/web/activity/activity_menu_patch.js
+++ b/addons/project_todo/static/src/web/activity/activity_menu_patch.js
@@ -11,6 +11,8 @@ import { useService } from "@web/core/utils/hooks";
 import { patch } from "@web/core/utils/patch";
 import { registry } from "@web/core/registry";
 
+const { DateTime } = luxon;
+
 // Add a to-do category for the command palette
 registry.category("command_categories").add("to-do", {}, { sequence: 105 });
 
@@ -87,7 +89,6 @@ patch(ActivityMenu.prototype, {
     },
 
     async saveTodo() {
-        const { DateTime } = luxon;
         const urlRegExp = /http(s)?:\/\/(www\.)?[a-zA-Z0-9@:%_+~#=~#?&/=\-;!.]{3,2000}/g;
         const todo = this.todoInputRef.el.value.replace(urlRegExp, '<a href="$&">$&</a>').trim();
         if (!todo) {
diff --git a/addons/project_todo/static/tests/activity_menu_tests.js b/addons/project_todo/static/tests/activity_menu_tests.js
index d4d9c7f2030..3ba0469e7b6 100644
--- a/addons/project_todo/static/tests/activity_menu_tests.js
+++ b/addons/project_todo/static/tests/activity_menu_tests.js
@@ -5,6 +5,8 @@ import { start } from "@mail/../tests/helpers/test_utils";
 import { editInput, patchDate } from "@web/../tests/helpers/utils";
 import { click, contains, insertText } from "@web/../tests/utils";
 
+const { DateTime } = luxon;
+
 QUnit.test("create todo from activity menu without date", async function () {
     await start();
     await contains(".o_menu_systray i[aria-label='Activities']");
@@ -47,9 +49,7 @@ QUnit.test("create todo from activity menu without date", async function () {
 
 QUnit.test("create to-do from activity menu with date", async function () {
     patchDate(2023, 1, 1, 6, 0, 0);
-    const { DateTime } = luxon;
-    const today = DateTime.utc();
-    const futureDay = today.plus({ days: 2 });
+    const futureDay = DateTime.utc().plus({ days: 2 });
     await start();
     await contains(".o_menu_systray i[aria-label='Activities']");
     await contains(".o-mail-ActivityMenu-counter", { count: 0 });
diff --git a/addons/project_todo/static/tests/helpers/mock_server/controller/project_todo.js b/addons/project_todo/static/tests/helpers/mock_server/controller/project_todo.js
index c2ee33bd6da..e4d8fbefb55 100644
--- a/addons/project_todo/static/tests/helpers/mock_server/controller/project_todo.js
+++ b/addons/project_todo/static/tests/helpers/mock_server/controller/project_todo.js
@@ -1,9 +1,10 @@
 /** @odoo-module **/
 
 import { patch } from "@web/core/utils/patch";
+import { serializeDate } from "@web/core/l10n/dates";
 import { MockServer } from '@web/../tests/helpers/mock_server';
 
-import { date_to_str } from '@web/legacy/js/core/time';
+const { DateTime } = luxon;
 
 patch(MockServer.prototype, {
     //--------------------------------------------------------------------------
@@ -33,7 +34,7 @@ patch(MockServer.prototype, {
         const taskId = this.pyEnv['project.task'].create({ description: values['todo_description'] });
         if (values['date_deadline']) {
             this.pyEnv['mail.activity'].create({
-                date_deadline: date_to_str(new Date(values['date_deadline'])),
+                date_deadline: serializeDate(DateTime.fromISO(values['date_deadline'])),
                 note: values['todo_description'],
                 res_model: 'project.task',
                 res_id: taskId,
diff --git a/addons/test_mail/static/tests/systray_activity_menu_tests.js b/addons/test_mail/static/tests/systray_activity_menu_tests.js
index eff42cfd565..fa398e250af 100644
--- a/addons/test_mail/static/tests/systray_activity_menu_tests.js
+++ b/addons/test_mail/static/tests/systray_activity_menu_tests.js
@@ -4,7 +4,7 @@ import { startServer } from "@bus/../tests/helpers/mock_python_environment";
 
 import { start } from "@mail/../tests/helpers/test_utils";
 
-import { date_to_str } from "@web/legacy/js/core/time";
+import { serializeDate, today } from "@web/core/l10n/dates";
 import { session } from "@web/session";
 import { patchWithCleanup } from "@web/../tests/helpers/utils";
 import { click, contains } from "@web/../tests/utils";
@@ -26,13 +26,12 @@ QUnit.test("menu with no records", async () => {
 });
 
 QUnit.test("do not show empty text when at least some future activities", async () => {
-    const tomorrow = new Date();
-    tomorrow.setDate(tomorrow.getDate() + 1);
+    const tomorrow = today().plus({ days: 1 });
     const pyEnv = await startServer();
     const activityId = pyEnv["mail.test.activity"].create({});
     pyEnv["mail.activity"].create([
         {
-            date_deadline: date_to_str(tomorrow),
+            date_deadline: serializeDate(tomorrow),
             res_id: activityId,
             res_model: "mail.test.activity",
         },
@@ -46,10 +45,8 @@ QUnit.test("do not show empty text when at least some future activities", async
 });
 
 QUnit.test("activity menu widget: activity menu with 2 models", async (assert) => {
-    const tomorrow = new Date();
-    tomorrow.setDate(tomorrow.getDate() + 1);
-    const yesterday = new Date();
-    yesterday.setDate(yesterday.getDate() - 1);
+    const tomorrow = today().plus({ days: 1 });
+    const yesterday = today().plus({ days: -1 });
     const pyEnv = await startServer();
     const partnerId = pyEnv["res.partner"].create({});
     const activityIds = pyEnv["mail.test.activity"].create([{}, {}, {}, {}]);
@@ -57,17 +54,17 @@ QUnit.test("activity menu widget: activity menu with 2 models", async (assert) =
         { res_id: partnerId, res_model: "res.partner" },
         { res_id: activityIds[0], res_model: "mail.test.activity" },
         {
-            date_deadline: date_to_str(tomorrow),
+            date_deadline: serializeDate(tomorrow),
             res_id: activityIds[1],
             res_model: "mail.test.activity",
         },
         {
-            date_deadline: date_to_str(tomorrow),
+            date_deadline: serializeDate(tomorrow),
             res_id: activityIds[2],
             res_model: "mail.test.activity",
         },
         {
-            date_deadline: date_to_str(yesterday),
+            date_deadline: serializeDate(yesterday),
             res_id: activityIds[3],
             res_model: "mail.test.activity",
         },
@@ -116,10 +113,8 @@ QUnit.test("activity menu widget: activity menu with 2 models", async (assert) =
 });
 
 QUnit.test("activity menu widget: activity view icon", async (assert) => {
-    const tomorrow = new Date();
-    tomorrow.setDate(tomorrow.getDate() + 1);
-    const yesterday = new Date();
-    yesterday.setDate(yesterday.getDate() - 1);
+    const tomorrow = today().plus({ days: 1 });
+    const yesterday = today().plus({ days: -1 });
     const pyEnv = await startServer();
     const partnerId = pyEnv["res.partner"].create({});
     const activityIds = pyEnv["mail.test.activity"].create([{}, {}, {}, {}]);
@@ -127,17 +122,17 @@ QUnit.test("activity menu widget: activity view icon", async (assert) => {
         { res_id: partnerId, res_model: "res.partner" },
         { res_id: activityIds[0], res_model: "mail.test.activity" },
         {
-            date_deadline: date_to_str(tomorrow),
+            date_deadline: serializeDate(tomorrow),
             res_id: activityIds[1],
             res_model: "mail.test.activity",
         },
         {
-            date_deadline: date_to_str(tomorrow),
+            date_deadline: serializeDate(tomorrow),
             res_id: activityIds[2],
             res_model: "mail.test.activity",
         },
         {
-            date_deadline: date_to_str(yesterday),
+            date_deadline: serializeDate(yesterday),
             res_id: activityIds[3],
             res_model: "mail.test.activity",
         },
diff --git a/addons/web/__manifest__.py b/addons/web/__manifest__.py
index 8328d20a5ef..3d028b75cbe 100644
--- a/addons/web/__manifest__.py
+++ b/addons/web/__manifest__.py
@@ -99,7 +99,6 @@ This module provides the core of the Odoo Web Client.
             'web/static/src/legacy/js/core/dom.js',
             'web/static/src/legacy/js/core/mixins.js',
             'web/static/src/legacy/js/core/service_mixins.js',
-            'web/static/src/legacy/js/core/time.js',
             'web/static/src/legacy/js/core/widget.js',
             'web/static/src/legacy/js/services/core.js',
 
@@ -222,7 +221,6 @@ This module provides the core of the Odoo Web Client.
             'web/static/src/legacy/js/core/dom.js',
             'web/static/src/legacy/js/core/mixins.js',
             'web/static/src/legacy/js/core/service_mixins.js',
-            'web/static/src/legacy/js/core/time.js',
             'web/static/src/legacy/js/core/widget.js',
             'web/static/src/legacy/js/services/core.js',
 
diff --git a/addons/web/static/src/legacy/js/core/time.js b/addons/web/static/src/legacy/js/core/time.js
deleted file mode 100644
index 647a70dc1e7..00000000000
--- a/addons/web/static/src/legacy/js/core/time.js
+++ /dev/null
@@ -1,305 +0,0 @@
-/** @odoo-module **/
-
-import { localization } from "@web/core/l10n/localization";
-import { _t } from "@web/core/l10n/translation";
-
-/**
- * Left-pad provided arg 1 with zeroes until reaching size provided by second
- * argument.
- *
- * @param {number|string} str value to pad
- * @param {number} size size to reach on the final padded value
- * @returns {string} padded string
- */
-function lpad(str, size) {
-    str = "" + str;
-    return new Array(size - str.length + 1).join('0') + str;
-}
-/**
- * @see lpad
- *
- * @param {string} str
- * @param {number} size
- * @returns {string}
- */
-function rpad(str, size) {
-    str = "" + str;
-    return str + new Array(size - str.length + 1).join('0');
-}
-
-/**
- * Replacer function for JSON.stringify, serializes Date objects to UTC
- * datetime in the OpenERP Server format.
- *
- * However, if a serialized value has a toJSON method that method is called
- * *before* the replacer is invoked. Date#toJSON exists, and thus the value
- * passed to the replacer is a string, the original Date has to be fetched
- * on the parent object (which is provided as the replacer's context).
- *
- * @param {String} k
- * @param {Object} v
- * @returns {Object}
- */
-export function date_to_utc (k, v) {
-    var value = this[k];
-    if (!(value instanceof Date)) { return v; }
-
-    return datetime_to_str(value);
-}
-
-/**
- * Converts a string to a Date javascript object using OpenERP's
- * datetime string format (exemple: '2011-12-01 15:12:35.832').
- *
- * The time zone is assumed to be UTC (standard for OpenERP 6.1)
- * and will be converted to the browser's time zone.
- *
- * @param {String} str A string representing a datetime.
- * @returns {Date}
- */
-export function str_to_datetime (str) {
-    if(!str) {
-        return str;
-    }
-    var regex = /^(\d\d\d\d)-(\d\d)-(\d\d) (\d\d):(\d\d):(\d\d(?:\.(\d+))?)$/;
-    var res = regex.exec(str);
-    if ( !res ) {
-        throw new Error("'" + str + "' is not a valid datetime");
-    }
-    var tmp = new Date(2000,0,1);
-    tmp.setUTCMonth(1970);
-    tmp.setUTCMonth(0);
-    tmp.setUTCDate(1);
-    tmp.setUTCFullYear(parseFloat(res[1]));
-    tmp.setUTCMonth(parseFloat(res[2]) - 1);
-    tmp.setUTCDate(parseFloat(res[3]));
-    tmp.setUTCHours(parseFloat(res[4]));
-    tmp.setUTCMinutes(parseFloat(res[5]));
-    tmp.setUTCSeconds(parseFloat(res[6]));
-    tmp.setUTCSeconds(parseFloat(res[6]));
-    tmp.setUTCMilliseconds(parseFloat(rpad((res[7] || "").slice(0, 3), 3)));
-    return tmp;
-}
-
-/**
- * Converts a string to a Date javascript object using OpenERP's
- * date string format (exemple: '2011-12-01').
- *
- * As a date is not subject to time zones, we assume it should be
- * represented as a Date javascript object at 00:00:00 in the
- * time zone of the browser.
- *
- * @param {String} str A string representing a date.
- * @returns {Date}
- */
-export function str_to_date (str) {
-    if(!str) {
-        return str;
-    }
-    var regex = /^(\d\d\d\d)-(\d\d)-(\d\d)$/;
-    var res = regex.exec(str);
-    if ( !res ) {
-        throw new Error("'" + str + "' is not a valid date");
-    }
-    var tmp = new Date(2000,0,1);
-    tmp.setFullYear(parseFloat(res[1]));
-    tmp.setMonth(parseFloat(res[2]) - 1);
-    tmp.setDate(parseFloat(res[3]));
-    tmp.setHours(0);
-    tmp.setMinutes(0);
-    tmp.setSeconds(0);
-    return tmp;
-}
-
-/**
- * Converts a string to a Date javascript object using OpenERP's
- * time string format (exemple: '15:12:35').
- *
- * The OpenERP times are supposed to always be naive times. We assume it is
- * represented using a javascript Date with a date 1 of January 1970 and a
- * time corresponding to the meant time in the browser's time zone.
- *
- * @param {String} str A string representing a time.
- * @returns {Date}
- */
-export function str_to_time (str) {
-    if(!str) {
-        return str;
-    }
-    var regex = /^(\d\d):(\d\d):(\d\d(?:\.(\d+))?)$/;
-    var res = regex.exec(str);
-    if ( !res ) {
-        throw new Error("'" + str + "' is not a valid time");
-    }
-    var tmp = new Date();
-    tmp.setFullYear(1970);
-    tmp.setMonth(0);
-    tmp.setDate(1);
-    tmp.setHours(parseFloat(res[1]));
-    tmp.setMinutes(parseFloat(res[2]));
-    tmp.setSeconds(parseFloat(res[3]));
-    tmp.setMilliseconds(parseFloat(rpad((res[4] || "").slice(0, 3), 3)));
-    return tmp;
-}
-
-/**
- * Converts a Date javascript object to a string using OpenERP's
- * datetime string format (exemple: '2011-12-01 15:12:35').
- *
- * The time zone of the Date object is assumed to be the one of the
- * browser and it will be converted to UTC (standard for OpenERP 6.1).
- *
- * @param {Date} obj
- * @returns {String} A string representing a datetime.
- */
-export function datetime_to_str (obj) {
-    if (!obj) {
-        return false;
-    }
-    return lpad(obj.getUTCFullYear(),4) + "-" + lpad(obj.getUTCMonth() + 1,2) + "-"
-         + lpad(obj.getUTCDate(),2) + " " + lpad(obj.getUTCHours(),2) + ":"
-         + lpad(obj.getUTCMinutes(),2) + ":" + lpad(obj.getUTCSeconds(),2);
-}
-
-/**
- * Converts a Date javascript object to a string using OpenERP's
- * date string format (exemple: '2011-12-01').
- *
- * As a date is not subject to time zones, we assume it should be
- * represented as a Date javascript object at 00:00:00 in the
- * time zone of the browser.
- *
- * @param {Date} obj
- * @returns {String} A string representing a date.
- */
-export function date_to_str (obj) {
-    if (!obj) {
-        return false;
-    }
-    return lpad(obj.getFullYear(),4) + "-" + lpad(obj.getMonth() + 1,2) + "-"
-         + lpad(obj.getDate(),2);
-}
-
-/**
- * Converts a Date javascript object to a string using OpenERP's
- * time string format (exemple: '15:12:35').
- *
- * The OpenERP times are supposed to always be naive times. We assume it is
- * represented using a javascript Date with a date 1 of January 1970 and a
- * time corresponding to the meant time in the browser's time zone.
- *
- * @param {Date} obj
- * @returns {String} A string representing a time.
- */
-export function time_to_str (obj) {
-    if (!obj) {
-        return false;
-    }
-    return lpad(obj.getHours(),2) + ":" + lpad(obj.getMinutes(),2) + ":"
-         + lpad(obj.getSeconds(),2);
-}
-
-export function auto_str_to_date (value) {
-    try {
-        return str_to_datetime(value);
-    } catch {}
-    try {
-        return str_to_date(value);
-    } catch {}
-    try {
-        return str_to_time(value);
-    } catch {}
-    throw new Error(_t("'%s' is not a correct date, datetime nor time", value));
-}
-
-export function auto_date_to_str (value, type) {
-    switch(type) {
-        case 'datetime':
-            return datetime_to_str(value);
-        case 'date':
-            return date_to_str(value);
-        case 'time':
-            return time_to_str(value);
-        default:
-            throw new Error(_t("'%s' is not convertible to date, datetime nor time", type));
-    }
-}
-
-const luxonToMomentFormatTable = {
-    c: "d",
-    d: "D",
-    o: "DDDD",
-    a: "A",
-    y: "Y",
-};
-
-function luxonToMomentFormat(format) {
-    return format.replace(/[a-zA-Z]/g, (match) => luxonToMomentFormatTable[match] || match);
-}
-
-/**
- * Get date format of the user's language
- */
-export function getLangDateFormat() {
-    return luxonToMomentFormat(localization.dateFormat);
-}
-
-/**
- * Get time format of the user's language
- */
-export function getLangTimeFormat() {
-    return luxonToMomentFormat(localization.timeFormat);
-}
-
-/**
- * Get date time format of the user's language
- */
-export function getLangDatetimeFormat() {
-    return luxonToMomentFormat(localization.dateTimeFormat);
-}
-
-const dateFormatWoZeroCache = {};
-/**
- * Get date format of the user's language - allows non padded
- */
-export function getLangDateFormatWoZero() {
-    const dateFormat = getLangDateFormat();
-    if (!(dateFormat in dateFormatWoZeroCache)) {
-        dateFormatWoZeroCache[dateFormat] = dateFormat
-            .replace('MM', 'M')
-            .replace('DD', 'D');
-    }
-    return dateFormatWoZeroCache[dateFormat];
-}
-
-const timeFormatWoZeroCache = {};
-/**
- * Get time format of the user's language - allows non padded
- */
-export function getLangTimeFormatWoZero() {
-    const timeFormat = getLangTimeFormat();
-    if (!(timeFormat in timeFormatWoZeroCache)) {
-        timeFormatWoZeroCache[timeFormat] = timeFormat
-            .replace('HH', 'H')
-            .replace('mm', 'm')
-            .replace('ss', 's');
-    }
-    return timeFormatWoZeroCache[timeFormat];
-}
-
-export default {
-    date_to_utc: date_to_utc,
-    str_to_datetime: str_to_datetime,
-    str_to_date: str_to_date,
-    str_to_time: str_to_time,
-    datetime_to_str: datetime_to_str,
-    date_to_str: date_to_str,
-    time_to_str: time_to_str,
-    auto_str_to_date: auto_str_to_date,
-    auto_date_to_str: auto_date_to_str,
-    getLangDateFormat: getLangDateFormat,
-    getLangTimeFormat: getLangTimeFormat,
-    getLangDateFormatWoZero: getLangDateFormatWoZero,
-    getLangTimeFormatWoZero: getLangTimeFormatWoZero,
-    getLangDatetimeFormat: getLangDatetimeFormat,
-};
diff --git a/addons/web/static/tests/legacy/core/time_tests.js b/addons/web/static/tests/legacy/core/time_tests.js
deleted file mode 100644
index 8e772606152..00000000000
--- a/addons/web/static/tests/legacy/core/time_tests.js
+++ /dev/null
@@ -1,163 +0,0 @@
-/** @odoo-module **/
-
-import { strftimeToLuxonFormat } from "@web/core/l10n/dates";
-import { localization } from "@web/core/l10n/localization";
-import time from "@web/legacy/js/core/time";
-
-QUnit.module('core', {}, function () {
-
-    QUnit.module('Time utils');
-
-    QUnit.test('Parse server datetime', function (assert) {
-        assert.expect(4);
-
-        var date = time.str_to_datetime("2009-05-04 12:34:23");
-        assert.deepEqual(
-            [date.getUTCFullYear(), date.getUTCMonth(), date.getUTCDate(),
-                date.getUTCHours(), date.getUTCMinutes(), date.getUTCSeconds()],
-            [2009, 5 - 1, 4, 12, 34, 23]);
-        assert.deepEqual(
-            [date.getFullYear(), date.getMonth(), date.getDate(),
-                date.getHours(), date.getMinutes(), date.getSeconds()],
-            [2009, 5 - 1, 4, 12 - (date.getTimezoneOffset() / 60), 34, 23]);
-
-        var date2 = time.str_to_datetime('2011-12-10 00:00:00');
-        assert.deepEqual(
-            [date2.getUTCFullYear(), date2.getUTCMonth(), date2.getUTCDate(),
-                date2.getUTCHours(), date2.getUTCMinutes(), date2.getUTCSeconds()],
-            [2011, 12 - 1, 10, 0, 0, 0]);
-
-        var date3 = time.str_to_datetime("2009-05-04 12:34:23.84565");
-        assert.deepEqual(
-            [date3.getUTCFullYear(), date3.getUTCMonth(), date3.getUTCDate(),
-                date3.getUTCHours(), date3.getUTCMinutes(), date3.getUTCSeconds(), date3.getUTCMilliseconds()],
-            [2009, 5 - 1, 4, 12, 34, 23, 845]);
-    });
-
-    QUnit.test('Parse server datetime on 31', function (assert) {
-        assert.expect(1);
-
-        var wDate = window.Date;
-
-        try {
-            window.Date = function (v) {
-                if (typeof v === "undefined") {
-                    v = '2013-10-31 12:34:56';
-                }
-                return new wDate(v);
-            };
-            var date = time.str_to_datetime('2013-11-11 02:45:21');
-
-            assert.deepEqual(
-                    [date.getUTCFullYear(), date.getUTCMonth(), date.getUTCDate(),
-                        date.getUTCHours(), date.getUTCMinutes(), date.getUTCSeconds()],
-                    [2013, 11 - 1, 11, 2, 45, 21]);
-        }
-        finally {
-            window.Date = wDate;
-        }
-    });
-
-    QUnit.test('Parse server date', function (assert) {
-        assert.expect(1);
-
-        var date = time.str_to_date("2009-05-04");
-        assert.deepEqual(
-            [date.getFullYear(), date.getMonth(), date.getDate()],
-            [2009, 5 - 1, 4]);
-    });
-
-    QUnit.test('Parse server date on 31', function (assert) {
-        assert.expect(1);
-
-        var wDate = window.Date;
-
-        try {
-            window.Date = function (v) {
-                if (typeof v === "undefined") {
-                    v = '2013-10-31 12:34:56';
-                }
-                return new wDate(v);
-            };
-            var date = time.str_to_date('2013-11-21');
-
-            assert.deepEqual(
-                [date.getFullYear(), date.getMonth(), date.getDate()],
-                [2013, 11 - 1, 21]);
-        }
-        finally {
-            window.Date = wDate;
-        }
-    });
-
-    QUnit.test('Parse server time', function (assert) {
-        assert.expect(2);
-
-        var date = time.str_to_time("12:34:23");
-        assert.deepEqual(
-            [date.getHours(), date.getMinutes(), date.getSeconds()],
-            [12, 34, 23]);
-
-        date = time.str_to_time("12:34:23.5467");
-        assert.deepEqual(
-            [date.getHours(), date.getMinutes(), date.getSeconds(), date.getMilliseconds()],
-            [12, 34, 23, 546]);
-    });
-
-    QUnit.test('Format server datetime', function (assert) {
-        assert.expect(1);
-
-        var date = new Date();
-        date.setUTCFullYear(2009);
-        date.setUTCMonth(5 - 1);
-        date.setUTCDate(4);
-        date.setUTCHours(12);
-        date.setUTCMinutes(34);
-        date.setUTCSeconds(23);
-        assert.strictEqual(time.datetime_to_str(date), "2009-05-04 12:34:23");
-    });
-
-    QUnit.test('Format server date', function (assert) {
-        assert.expect(1);
-
-        var date = new Date();
-        date.setUTCFullYear(2009);
-        date.setUTCMonth(5 - 1);
-        date.setUTCDate(4);
-        date.setUTCHours(0);
-        date.setUTCMinutes(0);
-        date.setUTCSeconds(0);
-        assert.strictEqual(time.date_to_str(date), "2009-05-04");
-    });
-
-    QUnit.test('Format server time', function (assert) {
-        assert.expect(1);
-
-        var date = new Date();
-        date.setUTCFullYear(1970);
-        date.setUTCMonth(1 - 1);
-        date.setUTCDate(1);
-        date.setUTCHours(0);
-        date.setUTCMinutes(0);
-        date.setUTCSeconds(0);
-        date.setHours(12);
-        date.setMinutes(34);
-        date.setSeconds(23);
-        assert.strictEqual(time.time_to_str(date), "12:34:23");
-    });
-
-    QUnit.test("Get lang datetime format", (assert) => {
-        assert.expect(4);
-        const originalParameters = Object.assign({}, localization);
-        Object.assign(localization, {
-            dateFormat: strftimeToLuxonFormat('%m/%d/%Y'),
-            timeFormat: strftimeToLuxonFormat('%H:%M:%S'),
-        });
-        assert.strictEqual(time.getLangDateFormat(), "MM/DD/YYYY");
-        assert.strictEqual(time.getLangDateFormatWoZero(), "M/D/YYYY");
-        assert.strictEqual(time.getLangTimeFormat(), "HH:mm:ss");
-        assert.strictEqual(time.getLangTimeFormatWoZero(), "H:m:s");
-        Object.assign(localization, originalParameters);
-    });
-
-});
diff --git a/addons/web_editor/__manifest__.py b/addons/web_editor/__manifest__.py
index e0a4c581335..fb89fb3b92a 100644
--- a/addons/web_editor/__manifest__.py
+++ b/addons/web_editor/__manifest__.py
@@ -86,7 +86,6 @@ Odoo Web Editor widget.
             'web/static/src/legacy/js/core/dom.js',
             'web/static/src/legacy/js/core/mixins.js',
             'web/static/src/legacy/js/core/service_mixins.js',
-            'web/static/src/legacy/js/core/time.js',
             'web/static/src/legacy/js/core/widget.js',
             'web/static/src/legacy/js/services/core.js',
             ('include', 'web_editor.assets_wysiwyg'),
diff --git a/addons/website_slides/__manifest__.py b/addons/website_slides/__manifest__.py
index 84067591aa8..d7d6b72720c 100644
--- a/addons/website_slides/__manifest__.py
+++ b/addons/website_slides/__manifest__.py
@@ -187,7 +187,6 @@ Featuring
             'web/static/src/legacy/js/core/dom.js',
             'web/static/src/legacy/js/core/mixins.js',
             'web/static/src/legacy/js/core/service_mixins.js',
-            'web/static/src/legacy/js/core/time.js',
             'web/static/src/legacy/js/core/widget.js',
             'web/static/src/legacy/js/services/core.js',
             'web/static/src/core/**/*.js',
diff --git a/addons/website_slides/static/src/js/slides.js b/addons/website_slides/static/src/js/slides.js
index 1a959b2a6e2..964eebfcd10 100644
--- a/addons/website_slides/static/src/js/slides.js
+++ b/addons/website_slides/static/src/js/slides.js
@@ -1,7 +1,7 @@
 /** @odoo-module **/
 
 import publicWidget from '@web/legacy/js/public/public_widget';
-import time from '@web/legacy/js/core/time';
+import { deserializeDateTime } from "@web/core/l10n/dates";
 const { DateTime } = luxon;
 
 publicWidget.registry.websiteSlides = publicWidget.Widget.extend({
@@ -16,7 +16,7 @@ publicWidget.registry.websiteSlides = publicWidget.Widget.extend({
 
         $("timeago.timeago").toArray().forEach((el) => {
             var datetime = $(el).attr('datetime');
-            var datetimeObj = time.str_to_datetime(datetime);
+            var datetimeObj = deserializeDateTime(datetime);
             // if presentation 7 days, 24 hours, 60 min, 60 second, 1000 millis old(one week)
             // then return fix formate string else timeago
             var displayStr = '';