diff --git a/addons/hr_holidays/__manifest__.py b/addons/hr_holidays/__manifest__.py
index e49f561e880..c380798da01 100644
--- a/addons/hr_holidays/__manifest__.py
+++ b/addons/hr_holidays/__manifest__.py
@@ -39,6 +39,7 @@ A synchronization with an internal agenda (Meetings of the CRM module) is also p
         'views/hr_leave_type_views.xml',
         'views/hr_leave_allocation_views.xml',
         'views/hr_leave_accrual_views.xml',
+        'views/hr_leave_stress_day_views.xml',
         'views/mail_activity_views.xml',
 
         'wizard/hr_holidays_cancel_leave_views.xml',
diff --git a/addons/hr_holidays/models/__init__.py b/addons/hr_holidays/models/__init__.py
index 1ab720a3edb..abd7f9a3688 100644
--- a/addons/hr_holidays/models/__init__.py
+++ b/addons/hr_holidays/models/__init__.py
@@ -9,6 +9,7 @@ from . import hr_leave_allocation
 from . import hr_leave_type
 from . import hr_leave_accrual_plan_level
 from . import hr_leave_accrual_plan
+from . import hr_leave_stress_day
 from . import mail_message_subtype
 from . import res_partner
 from . import res_users
diff --git a/addons/hr_holidays/models/hr_leave.py b/addons/hr_holidays/models/hr_leave.py
index bb30a34e52f..94bae63a9f2 100644
--- a/addons/hr_holidays/models/hr_leave.py
+++ b/addons/hr_holidays/models/hr_leave.py
@@ -278,6 +278,7 @@ class HolidaysRequest(models.Model):
     # view
     is_hatched = fields.Boolean('Hatched', compute='_compute_is_hatched')
     is_striked = fields.Boolean('Striked', compute='_compute_is_hatched')
+    has_stress_day = fields.Boolean(compute='_compute_has_stress_day')
 
     _sql_constraints = [
         ('type_value',
@@ -520,6 +521,34 @@ class HolidaysRequest(models.Model):
             else:
                 holiday.department_id = False
 
+    @api.depends('date_from', 'date_to', 'holiday_status_id')
+    def _compute_has_stress_day(self):
+        date_from, date_to = min(self.mapped('date_from')), max(self.mapped('date_to'))
+        resource_calendar_id = self.employee_id.resource_calendar_id or self.env.company.resource_calendar_id
+        if date_from and date_to:
+            stress_days = self.env['hr.leave.stress.day'].search([
+                ('start_date', '<=', date_to.date()),
+                ('end_date', '>=', date_from.date()),
+                '|',
+                    ('resource_calendar_id', '=', False),
+                    ('resource_calendar_id', 'in', resource_calendar_id.ids),
+            ])
+
+            for leave in self:
+                domain = [
+                    ('start_date', '<=', leave.date_to.date()),
+                    ('end_date', '>=', leave.date_from.date()),
+                    '|',
+                        ('resource_calendar_id', '=', False),
+                        ('resource_calendar_id', '=', (leave.employee_id.resource_calendar_id or self.env.company.resource_calendar_id).id)
+                ]
+
+                if leave.holiday_status_id.company_id:
+                    domain += [('company_id', '=', leave.holiday_status_id.company_id.id)]
+                leave.has_stress_day = leave.date_from and leave.date_to and stress_days.filtered_domain(domain)
+        else:
+            self.has_stress_day = False
+
     @api.depends('date_from', 'date_to', 'employee_id')
     def _compute_number_of_days(self):
         for holiday in self:
@@ -900,6 +929,12 @@ class HolidaysRequest(models.Model):
                         date=vstop
                     ))
 
+    @api.constrains('date_from', 'date_to')
+    def _check_stress_day(self):
+        is_leave_user = self.user_has_groups('hr_holidays.group_hr_holidays_user')
+        if not is_leave_user and any(leave.has_stress_day for leave in self):
+            raise ValidationError(_('You are not allowed to request a time off on a Stress Day.'))
+
     def _check_double_validation_rules(self, employees, state):
         if self.user_has_groups('hr_holidays.group_hr_holidays_manager'):
             return
diff --git a/addons/hr_holidays/models/hr_leave_stress_day.py b/addons/hr_holidays/models/hr_leave_stress_day.py
new file mode 100644
index 00000000000..62bd56bf30e
--- /dev/null
+++ b/addons/hr_holidays/models/hr_leave_stress_day.py
@@ -0,0 +1,42 @@
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+from dateutil.relativedelta import relativedelta
+from random import randint
+
+from odoo import api, fields, models
+
+
+class StressDay(models.Model):
+    _name = 'hr.leave.stress.day'
+    _description = 'Stress Day'
+    _order = 'start_date desc, end_date desc'
+
+    name = fields.Char(required=True)
+    company_id = fields.Many2one('res.company', default=lambda self: self.env.company, required=True)
+    start_date = fields.Date(required=True)
+    end_date = fields.Date(required=True)
+    color = fields.Integer(default=lambda dummy: randint(1, 11))
+    resource_calendar_id = fields.Many2one('resource.calendar', 'Working Hours',
+        default=lambda self: self.env.company.resource_calendar_id.id, domain="['|', ('company_id', '=', False), ('company_id', '=', company_id)]")
+
+    _sql_constraints = [
+        ('date_from_after_day_to', 'CHECK(start_date <= end_date)', 'The start date must be anterior than the end date.')
+    ]
+
+    @api.model
+    def get_stress_days(self, start_date, end_date, resource_calendar_id=None):
+        resource_calendar_id = resource_calendar_id or self.env.user.employee_id.resource_calendar_id or self.env.company.resource_calendar_id
+        all_days = {}
+        stress_days = self.env['hr.leave.stress.day'].search([
+            ('start_date', '>=', start_date),
+            ('end_date', '<=', end_date),
+            '|',
+                ('resource_calendar_id', '=', False),
+                ('resource_calendar_id', '=', resource_calendar_id.id),
+        ])
+
+        for stress_day in stress_days:
+            num_days = (stress_day.end_date - stress_day.start_date).days
+            for d in range(num_days + 1):
+                all_days[str(stress_day.start_date + relativedelta(days=d))] = stress_day.color
+
+        return all_days
diff --git a/addons/hr_holidays/security/hr_holidays_security.xml b/addons/hr_holidays/security/hr_holidays_security.xml
index f3f00790762..fe372159ae6 100644
--- a/addons/hr_holidays/security/hr_holidays_security.xml
+++ b/addons/hr_holidays/security/hr_holidays_security.xml
@@ -244,6 +244,12 @@
         <field name="domain_force">['|', ('company_id', '=', False), ('company_id', 'in', company_ids)]</field>
     </record>
 
+    <record id="hr_leave_stress_day_rule_multi_company" model="ir.rule">
+        <field name="name">Stress Day: multi company rule</field>
+        <field name="model_id" ref="model_hr_leave_stress_day"/>
+        <field name="domain_force">['|', ('company_id', '=', False), ('company_id', 'in', company_ids)]</field>
+    </record>
+
     <record id="hr_leave_report_calendar_rule_multi_company" model="ir.rule">
         <field name="name">Time Off Report Calendar: multi company global rule</field>
         <field name="model_id" ref="model_hr_leave_report_calendar"/>
diff --git a/addons/hr_holidays/security/ir.model.access.csv b/addons/hr_holidays/security/ir.model.access.csv
index 38a3ffc0580..f6979d41243 100644
--- a/addons/hr_holidays/security/ir.model.access.csv
+++ b/addons/hr_holidays/security/ir.model.access.csv
@@ -22,3 +22,5 @@ access_hr_leave_accrual_level_user,hr.leave.accrual.level.user,model_hr_leave_ac
 access_hr_leave_accrual_plan_manager,hr.leave.accrual.plan.manager,model_hr_leave_accrual_plan,hr_holidays.group_hr_holidays_manager,1,1,1,1
 access_hr_leave_accrual_level_manager,hr.leave.accrual.level.manager,model_hr_leave_accrual_level,hr_holidays.group_hr_holidays_manager,1,1,1,1
 access_hr_holidays_cancel_leave,access_hr_holidays_cancel_leave,hr_holidays.model_hr_holidays_cancel_leave,base.group_user,1,1,1,1
+access_hr_leave_stress_day_user,access_hr_holidays_stress_day_user,hr_holidays.model_hr_leave_stress_day,base.group_user,1,0,0,0
+access_hr_leave_stress_day_manager,access_hr_holidays_stress_day_manager,hr_holidays.model_hr_leave_stress_day,hr_holidays.group_hr_holidays_manager,1,1,1,1
diff --git a/addons/hr_holidays/static/src/js/time_off_calendar/time_off_calendar_controller.js b/addons/hr_holidays/static/src/js/time_off_calendar/time_off_calendar_controller.js
index 0ece094d944..c382f88ba04 100644
--- a/addons/hr_holidays/static/src/js/time_off_calendar/time_off_calendar_controller.js
+++ b/addons/hr_holidays/static/src/js/time_off_calendar/time_off_calendar_controller.js
@@ -104,6 +104,23 @@ export const TimeOffCalendarController = CalendarController.extend({
         }
     },
 
+    _update() {
+        return this._super(...arguments).then(() => {
+            this._rpc({
+                model: 'hr.leave.stress.day',
+                method: 'get_stress_days',
+                args: [this.model.data.start_date, this.model.data.end_date],
+                context: this.context,
+            }).then((stressDays) => {
+                this.$el.find('td.fc-day').toArray().forEach((td) => {
+                    if (stressDays[td.dataset.date]) {
+                        td.classList.add('hr_stress_day_' + stressDays[td.dataset.date]);
+                    }
+                });
+            });
+        });
+    },
+
     //--------------------------------------------------------------------------
     // Handlers
     //--------------------------------------------------------------------------
diff --git a/addons/hr_holidays/static/src/scss/time_off.scss b/addons/hr_holidays/static/src/scss/time_off.scss
index 00ce77d84c8..f8f139538ab 100644
--- a/addons/hr_holidays/static/src/scss/time_off.scss
+++ b/addons/hr_holidays/static/src/scss/time_off.scss
@@ -44,4 +44,23 @@
             font-size: 0.85rem;
         }
     }
+
+    @for $size from 1 through length($o-colors) {
+        .hr_stress_day_#{$size - 1} {
+            background-color: lighten(nth($o-colors, $size), 25%) !important;
+        }
+    }
+}
+
+.o_timeoff_dashboard_popover {
+    hr {
+        margin-top: 0px;
+        margin-bottom: 0px;
+    }
+
+    ul {
+        list-style: none;
+        padding-left: 0;
+        margin: 0px;
+    }
 }
diff --git a/addons/hr_holidays/tests/__init__.py b/addons/hr_holidays/tests/__init__.py
index c3160c237d7..c33839e85ec 100644
--- a/addons/hr_holidays/tests/__init__.py
+++ b/addons/hr_holidays/tests/__init__.py
@@ -12,3 +12,4 @@ from . import test_leave_requests
 from . import test_out_of_office
 from . import test_company_leave
 from . import test_res_partner
+from . import test_stress_days
diff --git a/addons/hr_holidays/tests/test_stress_days.py b/addons/hr_holidays/tests/test_stress_days.py
new file mode 100644
index 00000000000..4408d83d9b4
--- /dev/null
+++ b/addons/hr_holidays/tests/test_stress_days.py
@@ -0,0 +1,119 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+from datetime import datetime
+from freezegun import freeze_time
+
+from odoo import tests
+from odoo.tests import new_test_user
+from odoo.tests.common import Form, TransactionCase
+from odoo.exceptions import ValidationError
+
+
+@tests.tagged('access_rights', 'post_install', '-at_install')
+class TestHrLeaveStressDays(TransactionCase):
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+
+        cls.default_calendar = cls.env['resource.calendar'].create({
+            'name': 'moon calendar',
+        })
+
+        cls.company = cls.env['res.company'].create({
+            'name': 'super company',
+            'resource_calendar_id': cls.default_calendar.id,
+        })
+
+        cls.employee_user = new_test_user(cls.env, login='user', groups='base.group_user', company_ids=[(6, 0, cls.company.ids)], company_id=cls.company.id)
+        cls.manager_user = new_test_user(cls.env, login='manager', groups='base.group_user,hr_holidays.group_hr_holidays_manager', company_ids=[(6, 0, cls.company.ids)], company_id=cls.company.id)
+
+        cls.employee_emp = cls.env['hr.employee'].create({
+            'name': 'Toto Employee',
+            'company_id': cls.company.id,
+            'user_id': cls.employee_user.id,
+            'resource_calendar_id': cls.default_calendar.id,
+        })
+        cls.manager_emp = cls.env['hr.employee'].create({
+            'name': 'Toto Mananger',
+            'company_id': cls.company.id,
+            'user_id': cls.manager_user.id,
+        })
+
+        cls.leave_type = cls.env['hr.leave.type'].create({
+            'name': 'Unlimited',
+            'leave_validation_type': 'hr',
+            'requires_allocation': 'no',
+            'company_id': cls.company.id,
+        })
+
+        cls.stress_day = cls.env['hr.leave.stress.day'].create({
+            'name': 'Super Event',
+            'company_id': cls.company.id,
+            'start_date': datetime(2021, 11, 2),
+            'end_date': datetime(2021, 11, 2),
+            'color': 1,
+            'resource_calendar_id': cls.default_calendar.id,
+        })
+        cls.stress_week = cls.env['hr.leave.stress.day'].create({
+            'name': 'Super Event End Of Week',
+            'company_id': cls.company.id,
+            'start_date': datetime(2021, 11, 8),
+            'end_date': datetime(2021, 11, 12),
+            'color': 2,
+            'resource_calendar_id': cls.default_calendar.id,
+        })
+
+    @freeze_time('2021-10-15')
+    def test_request_stress_days(self):
+        # An employee can request time off outside stress days
+        self.env['hr.leave'].with_user(self.employee_user.id).create({
+            'name': 'coucou',
+            'holiday_status_id': self.leave_type.id,
+            'employee_id': self.employee_emp.id,
+            'date_from': datetime(2021, 11, 3),
+            'date_to': datetime(2021, 11, 3),
+            'number_of_days': 1,
+        })
+
+        # Taking a time off during a Stress Day is not allowed for a simple employee...
+        with self.assertRaises(ValidationError):
+            self.env['hr.leave'].with_user(self.employee_user.id).create({
+                'name': 'coucou',
+                'holiday_status_id': self.leave_type.id,
+                'employee_id': self.employee_emp.id,
+                'date_from': datetime(2021, 11, 3),
+                'date_to': datetime(2021, 11, 17),
+                'number_of_days': 1,
+            })
+
+        # ... but is allowed for a Time Off Officer
+        self.env['hr.leave'].with_user(self.manager_user.id).create({
+            'name': 'coucou',
+            'holiday_status_id': self.leave_type.id,
+            'employee_id': self.employee_emp.id,
+            'date_from': datetime(2021, 11, 2),
+            'date_to': datetime(2021, 11, 2),
+            'number_of_days': 1,
+        })
+
+    @freeze_time('2021-10-15')
+    def test_get_stress_days(self):
+        stress_days = self.env['hr.leave.stress.day'].with_user(self.employee_user.id).get_stress_days('2021-11-01', '2021-11-30')
+
+        # Stress Days spanning multiple days should be split in single days
+        expected_data = {'2021-11-02': 1, '2021-11-08': 2, '2021-11-09': 2, '2021-11-10': 2, '2021-11-11': 2, '2021-11-12': 2}
+
+        self.assertEqual(len(stress_days), len(expected_data))
+        for day, color in expected_data.items():
+            self.assertTrue(day in stress_days)
+            self.assertEqual(color, stress_days[day])
+
+        with self.assertRaises(ValidationError), Form(self.env['hr.leave'].with_user(self.employee_user.id).with_context(default_employee_id=self.employee_emp.id)) as leave_form:
+            leave_form.holiday_status_id = self.leave_type
+            leave_form.date_from = datetime(2021, 11, 1)
+            leave_form.date_to = datetime(2021, 11, 1)
+            self.assertFalse(leave_form.has_stress_day)
+
+            leave_form.date_to = datetime(2021, 11, 5)
+            self.assertTrue(leave_form.has_stress_day)
diff --git a/addons/hr_holidays/views/hr_holidays_views.xml b/addons/hr_holidays/views/hr_holidays_views.xml
index 959bfdc473a..9e41cd2d5f0 100644
--- a/addons/hr_holidays/views/hr_holidays_views.xml
+++ b/addons/hr_holidays/views/hr_holidays_views.xml
@@ -105,7 +105,7 @@
         groups="hr_holidays.group_hr_holidays_manager"
         sequence="2"/>
 
-    <menuitem   
+    <menuitem
         id="hr_holidays_public_time_off_menu_configuration"
         action="open_view_public_holiday"
         name="Public Holidays"
@@ -113,6 +113,14 @@
         groups="hr_holidays.group_hr_holidays_manager"
         sequence="3"/>
 
+    <menuitem
+        id="hr_holidays_stress_day_menu_configuration"
+        action="hr_leave_stress_day_action"
+        name="Stress Days"
+        parent="menu_hr_holidays_configuration"
+        groups="hr_holidays.group_hr_holidays_manager"
+        sequence="4"/>
+
     <menuitem id="hr_holidays_menu_config_activity_type"
         action="mail_activity_type_action_config_hr_holidays"
         parent="menu_hr_holidays_configuration"
diff --git a/addons/hr_holidays/views/hr_leave_stress_day_views.xml b/addons/hr_holidays/views/hr_leave_stress_day_views.xml
new file mode 100644
index 00000000000..5b8311ad2af
--- /dev/null
+++ b/addons/hr_holidays/views/hr_leave_stress_day_views.xml
@@ -0,0 +1,63 @@
+<?xml version='1.0' encoding='UTF-8' ?>
+<odoo>
+    <record id="hr_leave_stress_day_view_form" model="ir.ui.view">
+        <field name="model">hr.leave.stress.day</field>
+        <field name="arch" type="xml">
+            <form>
+                <sheet>
+                    <group>
+                        <group>
+                            <field name="name"/>
+                            <label for="start_date" string="Dates"/>
+                            <div class="o_row">
+                                <field name="start_date" nolabel="1" class="oe_inline" widget="daterange" options="{'related_end_date': 'end_date'}"/>
+                                <i class="fa fa-long-arrow-right mx-2" aria-label="Arrow icon" title="To"/>
+                                <field name="end_date" nolabel="1" class="oe_inline" widget="daterange" options="{'related_start_date': 'start_date'}"/>
+                            </div>
+                        </group>
+                        <group>
+                            <field name="color" widget="color_picker"/>
+                            <field name="company_id" groups="base.group_multi_company"/>
+                        </group>
+                    </group>
+                </sheet>
+            </form>
+        </field>
+    </record>
+
+    <record id="hr_leave_stress_day_view_list" model="ir.ui.view">
+        <field name="model">hr.leave.stress.day</field>
+        <field name="arch" type="xml">
+            <tree editable="bottom">
+                <field name="name"/>
+                <field name="company_id" groups="base.group_multi_company" optional="hide"/>
+                <field name="start_date"/>
+                <field name="end_date"/>
+                <field name="color" widget="color_picker" width="1"/>
+                <field name="resource_calendar_id" optional="hide"/>
+            </tree>
+        </field>
+    </record>
+
+    <record id="hr_leave_stress_day_view_search" model="ir.ui.view">
+        <field name="model">hr.leave.stress.day</field>
+        <field name="arch" type="xml">
+            <search string="Stress Days">
+                <field name="name"/>
+                <field name="start_date"/>
+                <field name="end_date"/>
+                <field name="company_id" groups="base.group_multi_company"/>
+                <separator />
+                <filter name="filter_date" date="start_date" default_period="this_year" string="Period"/>
+            </search>
+        </field>
+    </record>
+
+    <record id="hr_leave_stress_day_action" model="ir.actions.act_window">
+        <field name="name">Stress Days</field>
+        <field name="res_model">hr.leave.stress.day</field>
+        <field name="view_mode">tree,form</field>
+        <field name="search_view_id" ref="hr_leave_stress_day_view_search"/>
+        <field name="context">{'search_default_filter_date': True}</field>
+    </record>
+</odoo>
diff --git a/addons/hr_holidays/views/hr_leave_views.xml b/addons/hr_holidays/views/hr_leave_views.xml
index 2d60c3c0562..7aea31ae1e2 100644
--- a/addons/hr_holidays/views/hr_leave_views.xml
+++ b/addons/hr_holidays/views/hr_leave_views.xml
@@ -210,6 +210,7 @@
             <field name="can_approve" invisible="1"/>
             <field name="can_cancel" invisible="1"/>
             <field name="holiday_allocation_id" invisible="1" force_save="1"/>
+            <field name="has_stress_day" invisible="1"/>
             <header>
                 <button string="Confirm" name="action_confirm" type="object" class="oe_highlight" attrs="{'invisible': ['|', ('state', '!=', 'draft'), ('active', '=', False)]}"/>
                 <button string="Approve" name="action_approve" type="object" class="oe_highlight" attrs="{'invisible': ['|', '|', ('active', '=', False), ('can_approve', '=', False), ('state', '!=', 'confirm')]}"/>
@@ -315,8 +316,10 @@
                                         'required': [('request_unit_hours', '=', True)],
                                         'invisible': [('request_unit_hours', '=', False)]}"/>
                             </div>
+                            <div class="o_row mb-2 alert alert-warning text-justify" role="alert" attrs="{'invisible': [('has_stress_day', '=', False)]}">
+                                Your time off request covers one (or more) stress days. Taking time off during stress days is not authorized.
+                            </div>
                         </div>
-
                         <!-- When the user is leave manager, he should always see `number_of_days` to allow
                         him to edit the value. `number_of_hours_display` is only an informative field -->
                         <label for="number_of_days" string="Duration" attrs="{'invisible': [('request_unit_half', '=', True), ('leave_type_request_unit', '!=', 'hour')]}"/>