diff --git a/addons/hr_contract/models/hr_employee.py b/addons/hr_contract/models/hr_employee.py
index e98d02100fc..afe73bb6012 100644
--- a/addons/hr_contract/models/hr_employee.py
+++ b/addons/hr_contract/models/hr_employee.py
@@ -1,7 +1,9 @@
 # -*- coding: utf-8 -*-
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
-from datetime import date
+from pytz import UTC
+from datetime import date, datetime, time
+
 from odoo import api, fields, models
 from odoo.osv import expression
 
@@ -28,6 +30,7 @@ class Employee(models.Model):
 
     def _get_first_contract_date(self, no_gap=True):
         self.ensure_one()
+
         def remove_gap(contracts):
             # We do not consider a gap of more than 4 days to be a same occupation
             # contracts are considered to be ordered correctly
@@ -94,6 +97,29 @@ class Employee(models.Model):
         """
         return self.search(['|', ('active', '=', True), ('active', '=', False)])._get_contracts(date_from, date_to, states=states)
 
+    def _get_unusual_days(self, date_from, date_to=None):
+        employee_contracts = self.env['hr.contract'].search([
+            ('state', '!=', 'cancel'),
+            ('employee_id', '=', self.id),
+            ('date_start', '<=', date_to),
+            '|',
+            ('date_end', '=', False),
+            ('date_end', '>=', date_from),
+        ])
+        if not employee_contracts:
+            return super()._get_unusual_days(date_from, date_to)
+        unusual_days = {}
+        date_from_date = datetime.strptime(date_from, '%Y-%m-%d %H:%M:%S').date()
+        date_to_date = datetime.strptime(date_to, '%Y-%m-%d %H:%M:%S').date() if date_to else None
+        for contract in employee_contracts:
+            tmp_date_from = max(date_from_date, contract.date_start)
+            tmp_date_to = min(date_to_date, contract.date_end) if contract.date_end else date_to_date
+            unusual_days.update(contract.resource_calendar_id._get_unusual_days(
+                datetime.combine(fields.Date.from_string(tmp_date_from), time.min).replace(tzinfo=UTC),
+                datetime.combine(fields.Date.from_string(tmp_date_to), time.max).replace(tzinfo=UTC)
+            ))
+        return unusual_days
+
     def write(self, vals):
         res = super().write(vals)
         if vals.get('contract_id'):
diff --git a/addons/hr_holidays/models/hr_leave.py b/addons/hr_holidays/models/hr_leave.py
index c2b10cf5122..b63cdb3386a 100644
--- a/addons/hr_holidays/models/hr_leave.py
+++ b/addons/hr_holidays/models/hr_leave.py
@@ -1694,7 +1694,9 @@ class HolidaysRequest(models.Model):
 
     @api.model
     def get_unusual_days(self, date_from, date_to=None):
-        return self.env.user.employee_id.sudo(False)._get_unusual_days(date_from, date_to)
+        employee_id = self.env.context.get('employee_id', False)
+        employee = self.env['hr.employee'].browse(employee_id) if employee_id else self.env.user.employee_id
+        return employee.sudo(False)._get_unusual_days(date_from, date_to)
 
     def _get_start_or_end_from_attendance(self, hour, date, employee):
         hour = float_to_time(float(hour))
diff --git a/addons/hr_holidays/static/src/views/calendar/calendar_model.js b/addons/hr_holidays/static/src/views/calendar/calendar_model.js
index fdc8d84ba20..a3c3c138920 100644
--- a/addons/hr_holidays/static/src/views/calendar/calendar_model.js
+++ b/addons/hr_holidays/static/src/views/calendar/calendar_model.js
@@ -45,9 +45,25 @@ export class TimeOffCalendarModel extends CalendarModel {
 
     async updateData(data) {
         await super.updateData(data);
+
         data.stressDays = await this.fetchStressDays(data);
     }
 
+    /**
+     * @override
+     */
+    fetchUnusualDays(data) {
+        return this.orm.call(this.meta.resModel, "get_unusual_days", [
+            serializeDateTime(data.range.start),
+            serializeDateTime(data.range.end),
+        ],
+        {
+            context: {
+                'employee_id': this.employeeId,
+            }
+        });
+    }
+
     async fetchStressDays(data) {
         return this.orm.call("hr.employee", "get_stress_days", [
             this.employeeId,