diff --git a/addons/calendar/models/calendar_attendee.py b/addons/calendar/models/calendar_attendee.py
index f7240803c2d..ebcb8511de4 100644
--- a/addons/calendar/models/calendar_attendee.py
+++ b/addons/calendar/models/calendar_attendee.py
@@ -28,11 +28,12 @@ class Attendee(models.Model):
 
     event_id = fields.Many2one(
         'calendar.event', 'Meeting linked', required=True, ondelete='cascade')
-    partner_id = fields.Many2one('res.partner', 'Contact', required=True, readonly=True)
+    partner_id = fields.Many2one('res.partner', 'Attendee', required=True, readonly=True)
     state = fields.Selection(STATE_SELECTION, string='Status', readonly=True, default='needsAction',
                              help="Status of the attendee's participation")
     common_name = fields.Char('Common name', compute='_compute_common_name', store=True)
     email = fields.Char('Email', related='partner_id.email', help="Email of Invited Person")
+    phone = fields.Char('Phone', related='partner_id.phone', help="Phone number of Invited Person")
     availability = fields.Selection(
         [('free', 'Available'), ('busy', 'Busy')], 'Available/Busy', readonly=True)
     access_token = fields.Char('Invitation Token', default=_default_access_token)
diff --git a/addons/calendar/models/calendar_event.py b/addons/calendar/models/calendar_event.py
index 703fb6a4e94..adf3fc95934 100644
--- a/addons/calendar/models/calendar_event.py
+++ b/addons/calendar/models/calendar_event.py
@@ -127,7 +127,7 @@ class Meeting(models.Model):
         return self._get_recurrent_fields() | self._get_time_fields() | self._get_custom_fields() | {
             'id', 'active', 'allday',
             'duration', 'user_id', 'interval',
-            'count', 'rrule', 'recurrence_id', 'show_as'}
+            'count', 'rrule', 'recurrence_id', 'show_as', 'privacy'}
 
     @api.model
     def _get_display_time(self, start, stop, zduration, zallday):
@@ -217,15 +217,21 @@ class Meeting(models.Model):
     duration = fields.Float('Duration', compute='_compute_duration', store=True, readonly=False)
     description = fields.Text('Description')
     privacy = fields.Selection(
-        [('public', 'Everyone'),
-         ('private', 'Only me'),
+        [('public', 'Public'),
+         ('private', 'Private'),
          ('confidential', 'Only internal users')],
-        'Privacy', default='public', required=True)
+        'Privacy', default='public', required=True,
+        help="People to whom this event will be visible.")
     location = fields.Char('Location', tracking=True, help="Location of Event")
     videocall_location = fields.Char('Join Video Call', default=_default_videocall_location)
     show_as = fields.Selection(
         [('free', 'Available'),
-         ('busy', 'Busy')], 'Show Time as', default='busy', required=True)
+         ('busy', 'Busy')], 'Show as', default='busy', required=True,
+        help="If the time is shown as 'busy', this event will be visible to other people with either the full \
+        information or simply 'busy' written depending on its privacy. Use this option to let other people know \
+        that you are unavailable during that period of time. \n If the time is shown as 'free', this event won't \
+        be visible to other people at all. Use this option to let other people know that you are available during \
+        that period of time.")
 
     # linked document
     # LUL TODO use fields.Reference ?
@@ -253,12 +259,13 @@ class Meeting(models.Model):
         string='Attendees', default=_default_partners)
     alarm_ids = fields.Many2many(
         'calendar.alarm', 'calendar_alarm_calendar_event_rel',
-        string='Reminders', ondelete="restrict")
+        string='Reminders', ondelete="restrict",
+        help="Notifications sent to all attendees to remind of the meeting.")
     is_highlighted = fields.Boolean(
         compute='_compute_is_highlighted', string='Is the Event Highlighted')
 
     # RECURRENCE FIELD
-    recurrency = fields.Boolean('Recurrent', help="Recurrent Event")
+    recurrency = fields.Boolean('Recurrent')
     recurrence_id = fields.Many2one(
         'calendar.recurrence', string="Recurrence Rule", index=True)
     follow_recurrence = fields.Boolean(default=False) # Indicates if an event follows the recurrence, i.e. is not an exception
@@ -556,6 +563,29 @@ class Meeting(models.Model):
                 meeting.attendee_ids._send_mail_to_attendees('calendar.calendar_template_meeting_invitation')
         return True
 
+    def action_mass_mailing(self):
+        partners_ids = self.mapped('partner_ids')
+        if not partners_ids:
+            raise UserError(_("There are no attendees on these events"))
+        compose_form = self.env.ref('mail.email_compose_message_wizard_form', False)
+        default_partners = partners_ids and partners_ids.ids
+        compose_ctx = dict(
+            default_use_template=False,
+            default_composition_mode='mass_mail',
+            default_partner_ids=default_partners,
+            default_subject=_("Event update")
+        )
+        return {
+            'name': _('Contact Attendees'),
+            'type': 'ir.actions.act_window',
+            'view_mode': 'form',
+            'res_model': 'mail.compose.message',
+            'views': [(compose_form.id, 'form')],
+            'view_id': compose_form.id,
+            'target': 'new',
+            'context': compose_ctx,
+        }
+
     def _apply_recurrence_values(self, values, future=True):
         """Apply the new recurrence rules in `values`. Create a recurrence if it does not exist
         and create all missing events according to the rrule.
diff --git a/addons/calendar/models/calendar_event_type.py b/addons/calendar/models/calendar_event_type.py
index 14d92ebca38..c1c2b2513a5 100644
--- a/addons/calendar/models/calendar_event_type.py
+++ b/addons/calendar/models/calendar_event_type.py
@@ -1,6 +1,8 @@
 # -*- coding: utf-8 -*-
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
+from random import randint
+
 from odoo import fields, models
 
 
@@ -9,7 +11,11 @@ class MeetingType(models.Model):
     _name = 'calendar.event.type'
     _description = 'Event Meeting Type'
 
+    def _default_color(self):
+        return randint(1, 11)
+
     name = fields.Char('Name', required=True)
+    color = fields.Integer('Color', default=_default_color)
 
     _sql_constraints = [
         ('name_uniq', 'unique (name)', "Tag name already exists !"),
diff --git a/addons/calendar/static/src/js/calendar_controller.js b/addons/calendar/static/src/js/calendar_controller.js
index 190125ac722..1263e4c1993 100644
--- a/addons/calendar/static/src/js/calendar_controller.js
+++ b/addons/calendar/static/src/js/calendar_controller.js
@@ -4,9 +4,22 @@ odoo.define('calendar.CalendarController', function (require) {
     const Controller = require('web.CalendarController');
     const Dialog = require('web.Dialog');
     const { qweb, _t } = require('web.core');
+    const core = require('web.core');
+    const QWeb = core.qweb;
 
     const CalendarController = Controller.extend({
 
+    renderButtons: function ($node) {
+        this._super.apply(this, arguments);
+        const $addButton =  $(QWeb.render('Calendar.calendar_add_buttons'));
+        this.$buttons.prepend($addButton)
+        const self = this;
+        // When clicking on "Add", create a new record in form view
+        this.$buttons.on('click', 'button.o-calendar-button-new', () => {
+            return self.do_action('calendar.action_calendar_event_notify');
+        });
+    },
+
         _askRecurrenceUpdatePolicy() {
             return new Promise((resolve, reject) => {
                 new Dialog(this, {
@@ -25,7 +38,6 @@ odoo.define('calendar.CalendarController', function (require) {
             });
         },
 
-        // TODO factorize duplicated code
         /**
          * @override
          * @private
@@ -33,12 +45,7 @@ odoo.define('calendar.CalendarController', function (require) {
          */
         async _onDropRecord(event) {
             const _super = this._super; // reference to this._super is lost after async call
-            if (event.data.record.recurrency) {
-                const recurrenceUpdate = await this._askRecurrenceUpdatePolicy();
-                event.data = _.extend({}, event.data, {
-                    'recurrenceUpdate': recurrenceUpdate,
-                });
-            }
+            await this._dropdUpdateRecord(event);
             _super.apply(this, arguments);
         },
 
@@ -49,14 +56,18 @@ odoo.define('calendar.CalendarController', function (require) {
          */
         async _onUpdateRecord(event) {
             const _super = this._super;  // reference to this._super is lost after async call
+            await this._dropdUpdateRecord(event);
+            _super.apply(this, arguments);
+        },
+
+        async _dropdUpdateRecord(event) {
             if (event.data.record.recurrency) {
                 const recurrenceUpdate = await this._askRecurrenceUpdatePolicy();
                 event.data = _.extend({}, event.data, {
                     'recurrenceUpdate': recurrenceUpdate,
                 });
             }
-            _super.apply(this, arguments);
-        },
+        }
 
     });
 
diff --git a/addons/calendar/static/src/scss/calendar.scss b/addons/calendar/static/src/scss/calendar.scss
index 63cb48353aa..aafb36e2626 100644
--- a/addons/calendar/static/src/scss/calendar.scss
+++ b/addons/calendar/static/src/scss/calendar.scss
@@ -77,3 +77,7 @@
 .o_cw_body .o_clipboard_button {
     padding-top: 0px !important;
 }
+
+.o_calendar_attendees {
+    max-width:80% !important;
+}
diff --git a/addons/calendar/static/src/xml/base_calendar.xml b/addons/calendar/static/src/xml/base_calendar.xml
index f2f30f361f6..3f2b083477e 100644
--- a/addons/calendar/static/src/xml/base_calendar.xml
+++ b/addons/calendar/static/src/xml/base_calendar.xml
@@ -56,4 +56,10 @@
         </t>
     </t>
 
+     <t t-name="Calendar.calendar_add_buttons">
+        <span class="o_calendar_create_buttons">
+            <button class="btn btn-primary o-calendar-button-new" aria-label="Add" title="Add">Add</button>
+        </span>
+    </t>
+
 </template>
diff --git a/addons/calendar/views/calendar_views.xml b/addons/calendar/views/calendar_views.xml
index 3c707f03d8d..00754652788 100644
--- a/addons/calendar/views/calendar_views.xml
+++ b/addons/calendar/views/calendar_views.xml
@@ -6,7 +6,7 @@
         <field name="name">calendar.event.type</field>
         <field name="model">calendar.event.type</field>
         <field name="arch" type="xml">
-            <tree string="Meeting Types" editable="bottom">
+            <tree string="Meeting Types" sample="1" editable="bottom">
                 <field name="name"/>
             </tree>
         </field>
@@ -23,7 +23,7 @@
         <field name="name">calendar.alarm.tree</field>
         <field name="model">calendar.alarm</field>
         <field name="arch" type="xml">
-            <tree string="Calendar Alarm" editable="bottom">
+            <tree string="Calendar Alarm" sample="1" editable="bottom">
                 <field name="name" invisible="1"/>
                 <field name="alarm_type"/>
                 <field name="duration"/>
@@ -65,14 +65,25 @@
         <field name="name">calendar.event.tree</field>
         <field name="model">calendar.event</field>
         <field name="arch" type="xml">
-            <tree string="Meetings" multi_edit="1">
-                <field name="name" string="Subject" readonly="1"/>
-                <field name="allday" invisible="True"/>
-                <field name="start" string="Start Date"/>
-                <field name="stop" string="End Date"/>
-                <field name="partner_ids" readonly="1"/>
-                <field name="location"/>
+            <tree string="Meetings" sample="1" multi_edit="1">
+                <header>
+                    <button name="action_mass_mailing" type="object"
+                            string="Send Mail"/>
+                </header>
+                <field name="name" string="Subject" decoration-bf="1" attrs="{'readonly':[('recurrency','=',True)]}"/>
+                <field name="start" string="Start Date" readonly="1"/>
+                <field name="stop" string="End Date" readonly="1"/>
+                <field name="user_id" widget="many2one_avatar_user" attrs="{'readonly':[('recurrency','=',True)]}" optional="hide"/>
+                <field name="partner_ids" widget="many2many_tags" attrs="{'readonly':[('recurrency','=',True)]}" optional="show"/>
+                <field name="alarm_ids" widget="many2many_tags" optional="hide" attrs="{'readonly':[('recurrency','=',True)]}"/>
+                <field name="categ_ids" widget="many2many_tags" optional="hide" attrs="{'readonly':[('recurrency','=',True)]}"/>
+                <field name="recurrency" optional="hide" readonly="1"/>
+                <field name="privacy" optional="hide" attrs="{'readonly':[('recurrency','=',True)]}"/>
+                <field name="show_as" optional="hide" attrs="{'readonly':[('recurrency','=',True)]}"/>
+                <field name="location" optional="show" attrs="{'readonly':[('recurrency','=',True)]}"/>
                 <field name="duration" widget="float_time" readonly="1"/>
+                <field name="description" optional="hide" attrs="{'readonly':[('recurrency','=',True)]}"/>
+                <field name="allday" invisible="1"/>
                 <field name="message_needaction" invisible="1"/>
             </tree>
         </field>
@@ -104,12 +115,16 @@
                         <h1>
                             <field name="name" placeholder="e.g. Business Lunch"/>
                         </h1>
-                        <h2>
+                        <div class="d-flex">
                             <field name="partner_ids" widget="many2manyattendee"
                                 placeholder="Select attendees..."
                                 context="{'force_email':True}"
-                                class="oe_inline"/>
-                        </h2>
+                                class="oe_inline o_calendar_attendees"
+                            />
+                            <div name="send_buttons">
+                                <button name="action_mass_mailing" help="Send Email to attendees" type="object" string=" EMAIl" icon="fa-envelope"/>
+                            </div>
+                        </div>
                     </div>
                     <group>
                         <group>
@@ -125,20 +140,19 @@
                                     <field name="stop_date" string="Ending at" attrs="{'required': [('allday','=',True)],'invisible': [('allday','=',False)]}" force_save="1"/>
 
                                     <field name="start" string="Starting at" attrs="{'required': [('allday','=',False)], 'invisible': [('allday','=',True)]}"/>
-                                    <field name="stop" invisible="1"/>
+                                    <field name="stop" string="Ending At" attrs="{'invisible': [('allday','=',True)]}"/>
                                     <label for="duration" attrs="{'invisible': [('allday','=',True)]}"/>
                                     <div attrs="{'invisible': [('allday','=',True)]}">
                                         <field name="duration" widget="float_time" string="Duration" class="oe_inline" attrs="{'readonly': [('id', '!=', False), ('recurrency','=',True)]}"/>
                                         <span> hours</span>
                                     </div>
+                                     <field name="event_tz" attrs="{'invisible': [('recurrency', '=', False)]}"/>
                                     <field name="allday" attrs="{'readonly': [('id', '!=', False), ('recurrency','=',True)]}" force_save="1"/>
                                 </group>
                                 <group>
-                                    <field name="categ_ids" widget="many2many_tags" options="
-                                    {'no_create_edit': True}"/>
-                                    <field name="alarm_ids" widget="many2many_tags" />
+                                    <field name="alarm_ids" widget="many2many_tags" options="{'no_quick_create': True}"/>
                                     <field name="location" />
-                                    <field name="event_tz" attrs="{'invisible': [('recurrency', '=', False)]}"/>
+                                    <field name="categ_ids" widget="many2many_tags" options="{'color_field': 'color', 'no_create_edit': True}"/>
                                 </group>
 
                             </group>
@@ -200,12 +214,13 @@
                         </page>
 
                         <page name="page_invitations" string="Invitations" groups="base.group_no_one">
-                            <button name="action_sendmail" type="object" string="Send mail" icon="fa-envelope" class="oe_link"/>
+                            <button name="action_sendmail" type="object" string="Send Invitations" icon="fa-envelope" class="oe_link"/>
                             <field name="attendee_ids" widget="one2many" mode="tree,kanban">
                                 <tree string="Invitation details" editable="top" create="false" delete="false">
                                     <field name="partner_id" />
-                                    <field name="state" />
                                     <field name="email" widget="email"/>
+                                    <field name="phone" widget="phone"/>
+                                    <field name="state" />
 
                                     <button name="do_tentative" states="needsAction,declined,accepted" string="Uncertain" type="object" icon="fa-asterisk" />
                                     <button name="do_accept" string="Accept" states="needsAction,tentative,declined" type="object" icon="fa-check text-success"/>
@@ -259,13 +274,17 @@
                 event_open_popup="true"
                 event_limit="5"
                 color="user_id">
+                <field name="location" attrs="{'invisible': [('location', '=', False)]}"/>
                 <field name="videocall_location" string="Join Video Call" widget="CopyClipboardURL" />
-                <field name="attendee_status"/>
+                <field name="attendee_status" invisible="1"/>
                 <field name="user_id" string="Responsible" filters="1" widget="many2one_avatar_user"/>
                 <field name="partner_ids" widget="many2manyattendee" write_model="calendar.contacts" write_field="partner_id" avatar_field="image_128"/>
                 <field name="is_highlighted" invisible="1"/>
-                <field name="description"/>
+                <field name="description" attrs="{'invisible': [('description', '=', False)]}"/>
                 <field name="privacy"/>
+                <field name="show_as"/>
+                <field name="alarm_ids" attrs="{'invisible': [('alarm_ids', '=', [])]}"/>
+                <field name="categ_ids" attrs="{'invisible': [('categ_ids', '=', [])]}"/>
                 <!-- For recurrence update Dialog -->
                 <field name="recurrency" invisible="1"/>
                 <field name="recurrence_update" invisible="1"/>
@@ -280,13 +299,24 @@
             <search string="Search Meetings">
                 <field name="name" string="Meeting" filter_domain="[('name', 'ilike', self)]"/>
                 <field name="partner_ids"/>
-                <field name="categ_ids"/>
                 <field name="user_id"/>
+                <field name="location"/>
                 <field name="show_as"/>
+                <field name="categ_ids"/>
+                <field name="description"/>
                 <filter string="My Meetings" help="My Meetings" name="mymeetings" domain="[('partner_ids.user_ids', 'in', [uid])]"/>
                 <separator/>
                 <filter string="Date" name="filter_start_date" date="start"/>
                 <separator/>
+                <filter string="Busy" name="busy" domain="[('show_as', '=', 'busy')]"/>
+                <filter string="Free" name="free" domain="[('show_as', '=', 'free')]"/>
+                <separator/>
+                <filter string="Public" name="public" domain="[('privacy', '=', 'public')]"/>
+                <filter string="Private" name="private" domain="[('privacy', '=', 'private')]"/>
+                <filter string="Only Internal Users" name="confidential" domain="[('privacy', '=', 'confidential')]"/>
+                <separator/>
+                <filter string="Recurrent" name="recurrent" domain="[('recurrency', '=', True)]"/>
+                <separator/>
                 <filter string="Archived" name="inactive" domain="[('active', '=', False)]"/>
                 <group expand="0" string="Group By">
                     <filter string="Responsible" name="responsible" domain="[]" context="{'group_by': 'user_id'}"/>
@@ -304,7 +334,7 @@
         <field name="search_view_id" ref="view_calendar_event_search"/>
         <field name="help" type="html">
           <p class="o_view_nocontent_smiling_face">
-            Schedule a new meeting
+            No meetings found. Let's schedule one!
           </p><p>
             The calendar is shared between employees and fully integrated with
             other applications such as the employee leaves or the business
@@ -357,6 +387,21 @@
         web_icon="calendar,static/description/icon.png"
         groups="base.group_user"/>
 
+    <menuitem
+        id="calendar_menu_config"
+        parent="calendar.mail_menu_calendar"
+        name="Configuration"
+        sequence="40"
+        action="calendar.action_calendar_event"
+        groups="base.group_no_one"/>
+
+    <menuitem
+        id="calendar_submenu_reminders"
+        parent="calendar_menu_config"
+        name="Reminders"
+        action="action_calendar_alarm"
+        groups="base.group_no_one"/>
+
     <menuitem
         id="menu_calendar_configuration"
         name="Calendar"
diff --git a/addons/calendar_sms/models/calendar.py b/addons/calendar_sms/models/calendar.py
index 5c42e2754a2..cb3ca29ecd0 100644
--- a/addons/calendar_sms/models/calendar.py
+++ b/addons/calendar_sms/models/calendar.py
@@ -27,6 +27,19 @@ class CalendarEvent(models.Model):
                 put_in_queue=False
             )
 
+    def action_send_sms(self):
+        return {
+            'type': 'ir.actions.act_window',
+            'res_model': 'sms.composer',
+            'view_mode': 'form',
+            'target': 'new',
+            'context': {
+                'default_composition_mode': 'mass',
+                'default_res_model': 'res.partner',
+                'default_res_ids': self.partner_ids.ids,
+            },
+        }
+
     def _get_trigger_alarm_types(self):
         return super()._get_trigger_alarm_types() + ['sms']
 
diff --git a/addons/calendar_sms/views/calendar_views.xml b/addons/calendar_sms/views/calendar_views.xml
index d1c13e964d3..ea7def35501 100644
--- a/addons/calendar_sms/views/calendar_views.xml
+++ b/addons/calendar_sms/views/calendar_views.xml
@@ -3,12 +3,12 @@
 
     <!-- Add action entry in the Action Menu for Events -->
     <record id="calendar_event_act_window_sms_composer_single" model="ir.actions.act_window">
-        <field name="name">Send SMS to attendees</field>
+        <field name="name">Send SMS</field>
         <field name="res_model">sms.composer</field>
         <field name="view_mode">form</field>
         <field name="target">new</field>
         <field name="context">{
-            'sms_composition_mode': 'guess',
+            'default_composition_mode': 'guess',
             'default_res_id': active_id,
             'default_res_ids': active_ids,
         }</field>
@@ -19,11 +19,20 @@
         <field name="model">calendar.event</field>
         <field name="inherit_id" ref="calendar.view_calendar_event_tree"/>
         <field name="arch" type="xml">
-            <xpath expr="//tree" position="inside">
-                <header>
-                    <button name="%(calendar_event_act_window_sms_composer_single)d" type="action"
-                            string="Send SMS to attendees"/>
-                </header>
+            <xpath expr="//header" position="inside">
+                <button name="%(calendar_event_act_window_sms_composer_single)d" type="action"
+                        string="Send SMS"/>
+            </xpath>
+        </field>
+    </record>
+
+    <record id="view_calendar_event_form_inherited" model="ir.ui.view">
+        <field name="name">calendar.event.form.calendar_sms</field>
+        <field name="model">calendar.event</field>
+        <field name="inherit_id" ref="calendar.view_calendar_event_form"/>
+        <field name="arch" type="xml">
+            <xpath expr="//div[@name='send_buttons']" position="inside">
+                <button name="action_send_sms" help="Send SMS to attendees" type="object" string="SMS" icon="fa-mobile"/>
             </xpath>
         </field>
     </record>
diff --git a/addons/crm/views/calendar_views.xml b/addons/crm/views/calendar_views.xml
index 8267a60558d..7d001ebff10 100644
--- a/addons/crm/views/calendar_views.xml
+++ b/addons/crm/views/calendar_views.xml
@@ -6,7 +6,7 @@
         <field name="model">calendar.event</field>
         <field name="inherit_id" ref="calendar.view_calendar_event_search"/>
         <field name="arch" type="xml">
-            <xpath expr="//field[@name='user_id']" position="after">
+            <xpath expr="//field[@name='description']" position="after">
                 <field name="opportunity_id"/>
             </xpath>
         </field>
diff --git a/addons/google_calendar/views/res_config_settings_views.xml b/addons/google_calendar/views/res_config_settings_views.xml
index 6df09e85354..431c40e4cbc 100644
--- a/addons/google_calendar/views/res_config_settings_views.xml
+++ b/addons/google_calendar/views/res_config_settings_views.xml
@@ -13,7 +13,6 @@
                             <label for="cal_client_secret" string="Client Secret" class="col-3 col-lg-3 o_light_label"/>
                             <field name="cal_client_secret" password="True" nolabel="1"/>
                         </div>
-                        <a href="https://www.odoo.com/documentation/user/14.0/crm/optimize/google_calendar_credentials.html" class="oe-link" target="_blank"><i class="fa fa-fw fa-arrow-right"/>Tutorial</a>
                     </div>
                 </div>
             </field>