diff --git a/addons/contacts/__manifest__.py b/addons/contacts/__manifest__.py
index 0a910c80538..0e7702f34ad 100644
--- a/addons/contacts/__manifest__.py
+++ b/addons/contacts/__manifest__.py
@@ -15,6 +15,9 @@ You can track your vendors, customers and other contacts.
     'data': [
         'views/contact_views.xml',
     ],
+    'demo': [
+        'data/mail_demo.xml',
+    ],
     'application': True,
     'license': 'LGPL-3',
     'assets': {
diff --git a/addons/contacts/data/mail_demo.xml b/addons/contacts/data/mail_demo.xml
new file mode 100644
index 00000000000..12eb254cbd0
--- /dev/null
+++ b/addons/contacts/data/mail_demo.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<odoo><data noupdate="1">
+
+    <!-- Message with scheduled notification -->
+    <record id="message_demo_partner_2_0" model="mail.message">
+        <field name="author_id" ref="base.partner_demo"/>
+        <field name="body" type="html"><p>Hello! Could you send us your address ?</p></field>
+        <field name="date" eval="(DateTime.today() - timedelta(days=1)).strftime('%Y-%m-%d %H:%M:00')"/>
+        <field name="model">res.partner</field>
+        <field name="res_id" ref="base.res_partner_2"/>
+        <field name="message_type">email</field>
+        <field name="subtype_id" ref="mail.mt_comment"/>
+    </record>
+    <record id="message_demo_partner_1_5_notif_0" model="mail.message.schedule">
+        <field name="mail_message_id" ref="message_demo_partner_2_0"/>
+        <field name="scheduled_datetime" eval="(DateTime.today() + timedelta(days=2)).strftime('%Y-%m-%d %H:%M:00')"/>
+    </record>
+
+</data></odoo>
diff --git a/addons/im_livechat/tests/test_message.py b/addons/im_livechat/tests/test_message.py
index 3957660a45c..79a8a2c4b7d 100644
--- a/addons/im_livechat/tests/test_message.py
+++ b/addons/im_livechat/tests/test_message.py
@@ -73,6 +73,7 @@ class TestImLivechatMessage(TransactionCase):
             'recipients': [],
             'record_name': "test1 Ernest Employee",
             'res_id': channel_livechat_1.id,
+            'scheduledDatetime': False,
             'sms_ids': [],
             'starred_partner_ids': [],
             'subject': False,
diff --git a/addons/mail/models/mail_message.py b/addons/mail/models/mail_message.py
index 03456375469..4ef8133eaef 100644
--- a/addons/mail/models/mail_message.py
+++ b/addons/mail/models/mail_message.py
@@ -904,10 +904,17 @@ class Message(models.Model):
             domain = expression.AND([domain, [('id', '>', min_id)]])
         return self.search(domain, limit=limit)
 
-    def message_format(self, format_reply=True):
-        """ Get the message values in the format for web client. Since message values can be broadcasted,
-            computed fields MUST NOT BE READ and broadcasted.
-            :returns list(dict).
+    def message_format(self, format_reply=True, msg_vals=None):
+        """ Get the message values in the format for web client. Since message
+        values can be broadcasted, computed fields MUST NOT BE READ and
+        broadcasted.
+
+        :param msg_vals: dictionary of values used to create the message. If
+          given it may be used to access values related to ``message`` without
+          accessing it directly. It lessens query count in some optimized use
+          cases by avoiding access message content in db;
+
+        :returns list(dict).
              Example :
                 {
                     'body': HTML content of the message
@@ -958,6 +965,19 @@ class Message(models.Model):
         com_id = self.env['ir.model.data']._xmlid_to_res_id('mail.mt_comment')
         note_id = self.env['ir.model.data']._xmlid_to_res_id('mail.mt_note')
 
+
+        # fetch scheduled notifications once, only if msg_vals is not given to
+        # avoid useless queries when notifying Inbox right after a message_post
+        scheduled_dt_by_msg_id = {}
+        if msg_vals:
+            scheduled_dt_by_msg_id = {msg.id: msg_vals.get('scheduled_date') for msg in self}
+        elif self:
+            schedulers = self.env['mail.message.schedule'].sudo().search([
+                ('mail_message_id', 'in', self.ids)
+            ])
+            for scheduler in schedulers:
+                scheduled_dt_by_msg_id[scheduler.mail_message_id.id] = scheduler.scheduled_datetime
+
         for vals in vals_list:
             message_sudo = self.browse(vals['id']).sudo().with_prefetch(self.ids)
             notifs = message_sudo.notification_ids.filtered(lambda n: n.res_partner_id)
@@ -969,6 +989,7 @@ class Message(models.Model):
                 'subtype_description': message_sudo.subtype_id.description,
                 'is_notification': vals['message_type'] == 'user_notification',
                 'recipients': [{'id': p.id, 'name': p.name} for p in message_sudo.partner_ids],
+                'scheduledDatetime': scheduled_dt_by_msg_id.get(vals['id'], False),
             })
             if vals['model'] and self.env[vals['model']]._original_module:
                 vals['module_icon'] = modules.module.get_module_icon(self.env[vals['model']]._original_module)
diff --git a/addons/mail/models/mail_thread.py b/addons/mail/models/mail_thread.py
index f65807673d2..dd60edc395a 100644
--- a/addons/mail/models/mail_thread.py
+++ b/addons/mail/models/mail_thread.py
@@ -2857,7 +2857,7 @@ class MailThread(models.AbstractModel):
             } for pid in inbox_pids]
             self.env['mail.notification'].sudo().create(notif_create_values)
 
-            message_format_values = message.message_format()[0]
+            message_format_values = message.message_format(msg_vals=msg_vals)[0]
             for partner_id in inbox_pids:
                 bus_notifications.append((self.env['res.partner'].browse(partner_id), 'mail.message/inbox', dict(message_format_values)))
         self.env['bus.bus'].sudo()._sendmany(bus_notifications)
diff --git a/addons/mail/static/src/components/message/message.xml b/addons/mail/static/src/components/message/message.xml
index ed5c98dfcfd..e96eef8fa04 100644
--- a/addons/mail/static/src/components/message/message.xml
+++ b/addons/mail/static/src/components/message/message.xml
@@ -76,6 +76,11 @@
                                 on <a class="o_MessageView_originThreadLink fs-6" t-att-href="message.originThread.url" t-on-click="onClickOriginThread"><t t-if="message.originThread.displayName"><t t-esc="message.originThread.displayName"/></t><t t-else="">document</t></a>
                             </t>
                         </small>
+                        <div t-if="message.scheduledDatetime" class="o_MessageView_headerScheduledDatetime" t-att-class="{ 'ms-2': isInChatWindowAndIsAlignedRight }" t-att-title="scheduledFromNow">
+                            <span class="text-600 cursor-pointer">
+                                <i class="fa fa-calendar-o"></i>
+                            </span>
+                        </div>
                         <div t-if="messageListViewItemOwner and message.originThread and message.originThread === messageListViewItemOwner.messageListViewOwner.threadViewOwner.thread and message.notifications.length > 0" t-att-class="{ 'ms-2': isInChatWindowAndIsAlignedRight }">
                             <span t-if="message.failureNotifications.length > 0" class="o_MessageView_notificationIconClickable o-error cursor-pointer text-danger" role="button" tabindex="0" t-on-click="onClickFailure">
                                 <i class="o_MessageView_notificationIcon" t-att-class="failureNotificationIconClassName" role="img" aria-label="Delivery failure"/> <span t-if="failureNotificationIconLabel" t-out="failureNotificationIconLabel"/>
diff --git a/addons/mail/static/src/models/message.js b/addons/mail/static/src/models/message.js
index 17bae319e1b..70d2e56d8f1 100644
--- a/addons/mail/static/src/models/message.js
+++ b/addons/mail/static/src/models/message.js
@@ -99,6 +99,9 @@ Model({
             if ("recipients" in data) {
                 data2.recipients = data.recipients;
             }
+            if ("scheduledDatetime" in data) {
+                data2.scheduledDatetime = data.scheduledDatetime;
+            }
             if ("starred_partner_ids" in data && this.messaging.currentPartner) {
                 data2.isStarred = data.starred_partner_ids.includes(
                     this.messaging.currentPartner.id
@@ -698,6 +701,23 @@ Model({
             },
         }),
         recipients: many("Partner"),
+        /**
+         * In case of delayed notification, a scheduled datetime linked to the
+         * message scheduler is given in order to display it new to the post
+         * datetime.
+         */
+        scheduledDatetime: attr(),
+        scheduledMomentDate: attr({
+            compute() {
+                if (!this.scheduledDatetime) {
+                    return clear();
+                }
+                if (!moment.isMoment(this.scheduledDatetime)) {
+                    return moment(str_to_datetime(this.scheduledDatetime));
+                }
+                return this.scheduledDatetime;
+            },
+        }),
         shortTime: attr({
             compute() {
                 if (!this.momentDate) {
diff --git a/addons/mail/static/src/models/message_view.js b/addons/mail/static/src/models/message_view.js
index d488451344c..b685547f642 100644
--- a/addons/mail/static/src/models/message_view.js
+++ b/addons/mail/static/src/models/message_view.js
@@ -713,5 +713,22 @@ Model({
                 return this.env._t("Read More");
             },
         }),
+        /**
+         * Scheduled for sending
+         */
+        scheduledFromNow: attr({
+            compute() {
+                if (!this.message) {
+                    return clear();
+                }
+                if (!this.message.scheduledMomentDate) {
+                    return clear();
+                }
+                if (!this.clockWatcher.clock.date) {
+                    return clear();
+                }
+                return this.message.scheduledMomentDate.fromNow();
+            },
+        }),
     },
 });
diff --git a/addons/rating/models/mail_message.py b/addons/rating/models/mail_message.py
index dcd72234c3b..5a8419af34a 100644
--- a/addons/rating/models/mail_message.py
+++ b/addons/rating/models/mail_message.py
@@ -26,8 +26,8 @@ class MailMessage(models.Model):
         ])
         return [('id', 'in', ratings.mapped('message_id').ids)]
 
-    def message_format(self, format_reply=True):
-        message_values = super().message_format(format_reply=format_reply)
+    def message_format(self, format_reply=True, msg_vals=None):
+        message_values = super().message_format(format_reply=format_reply, msg_vals=msg_vals)
         rating_mixin_messages = self.filtered(lambda message:
             message.model
             and message.res_id
diff --git a/addons/sms/models/mail_message.py b/addons/sms/models/mail_message.py
index e3a4c67c5df..65906097a84 100644
--- a/addons/sms/models/mail_message.py
+++ b/addons/sms/models/mail_message.py
@@ -33,13 +33,13 @@ class MailMessage(models.Model):
             return ['&', ('notification_ids.notification_status', '=', 'exception'), ('notification_ids.notification_type', '=', 'sms')]
         raise NotImplementedError()
 
-    def message_format(self, format_reply=True):
+    def message_format(self, format_reply=True, msg_vals=None):
         """ Override in order to retrieves data about SMS (recipient name and
             SMS status)
 
         TDE FIXME: clean the overall message_format thingy
         """
-        message_values = super(MailMessage, self).message_format(format_reply=format_reply)
+        message_values = super(MailMessage, self).message_format(format_reply=format_reply, msg_vals=msg_vals)
         all_sms_notifications = self.env['mail.notification'].sudo().search([
             ('mail_message_id', 'in', [r['id'] for r in message_values]),
             ('notification_type', '=', 'sms')
diff --git a/addons/test_mail/tests/test_performance.py b/addons/test_mail/tests/test_performance.py
index 914f0542f45..ba1b99a8ecd 100644
--- a/addons/test_mail/tests/test_performance.py
+++ b/addons/test_mail/tests/test_performance.py
@@ -1187,7 +1187,7 @@ class TestMailComplexPerformance(BaseMailPerformance):
             ]
         }])
 
-        with self.assertQueryCount(employee=6):
+        with self.assertQueryCount(employee=7):
             res = messages.message_format()
             self.assertEqual(len(res), 2)
             for message in res:
@@ -1196,7 +1196,7 @@ class TestMailComplexPerformance(BaseMailPerformance):
         self.env.flush_all()
         self.env.invalidate_all()
 
-        with self.assertQueryCount(employee=19):
+        with self.assertQueryCount(employee=20):
             res = messages.message_format()
             self.assertEqual(len(res), 2)
             for message in res:
@@ -1217,14 +1217,14 @@ class TestMailComplexPerformance(BaseMailPerformance):
             'res_id': record.id
         } for record in records])
 
-        with self.assertQueryCount(employee=5):
+        with self.assertQueryCount(employee=6):
             res = messages.message_format()
             self.assertEqual(len(res), 6)
 
         self.env.flush_all()
         self.env.invalidate_all()
 
-        with self.assertQueryCount(employee=14):
+        with self.assertQueryCount(employee=15):
             res = messages.message_format()
             self.assertEqual(len(res), 6)