diff --git a/addons/project_timesheet_holidays/models/resource_calendar_leaves.py b/addons/project_timesheet_holidays/models/resource_calendar_leaves.py
index 90bef97cfcd..9e208eabb7b 100644
--- a/addons/project_timesheet_holidays/models/resource_calendar_leaves.py
+++ b/addons/project_timesheet_holidays/models/resource_calendar_leaves.py
@@ -151,15 +151,16 @@ class ResourceCalendarLeaves(models.Model):
         return results
 
     def write(self, vals):
-        start_dates = self.mapped('date_from')
-        end_dates = self.mapped('date_to')
+        date_from, date_to, calendar_id = vals.get('date_from'), vals.get('date_to'), vals.get('calendar_id')
+        global_time_off_updated = self.env['resource.calendar.leaves']
+        if date_from or date_to or 'calendar_id' in vals:
+            global_time_off_updated = self.filtered(lambda r: (date_from is not None and r.date_from != date_from) or (date_to is not None and r.date_to != date_to) or (calendar_id is not None and r.calendar_id.id != calendar_id))
+            timesheets = global_time_off_updated.sudo().timesheet_ids
+            if timesheets:
+                timesheets.write({'global_leave_id': False})
+                timesheets.unlink()
         result = super(ResourceCalendarLeaves, self).write(vals)
-        date_from, date_to = vals.get('date_from'), vals.get('date_to')
-        if date_from or date_to:
-            if any(start_date != date_from or end_date != date_to for start_date, end_date in zip(start_dates, end_dates)):
-                timesheets = self.mapped('timesheet_ids')
-                if timesheets:
-                    timesheets.write({'global_leave_id': False})
-                    timesheets.unlink()
-                    self._timesheet_create_lines()
+        if global_time_off_updated:
+            global_time_offs_with_leave_timesheet = global_time_off_updated.filtered(lambda r: not r.resource_id and r.calendar_id.company_id.internal_project_id and r.calendar_id.company_id.leave_timesheet_task_id)
+            global_time_offs_with_leave_timesheet._timesheet_create_lines()
         return result
diff --git a/addons/project_timesheet_holidays/tests/test_timesheet_global_time_off.py b/addons/project_timesheet_holidays/tests/test_timesheet_global_time_off.py
index 689de00145a..0112b111992 100644
--- a/addons/project_timesheet_holidays/tests/test_timesheet_global_time_off.py
+++ b/addons/project_timesheet_holidays/tests/test_timesheet_global_time_off.py
@@ -139,3 +139,39 @@ class TestTimesheetGlobalTimeOff(common.TransactionCase):
         # No timesheet should have been created on the day off
         timesheet = self.env['account.analytic.line'].search([('date', '=', day_off), ('task_id', '=', leave_task.id)])
         self.assertFalse(timesheet.id)
+
+    # This tests that timesheets are created/deleted for every employee with the same calendar
+    # when a global time off has a calendar_id set/remove
+    def test_timesheet_creation_and_deletion_for_calendar_set_and_remove(self):
+        leave_start_datetime = datetime(2021, 1, 4, 7, 0, 0, 0)  # This is a monday
+        leave_end_datetime = datetime(2021, 1, 8, 18, 0, 0, 0)  # This is a friday
+
+        global_time_off = self.env['resource.calendar.leaves'].create({
+            'name': 'Test',
+            'calendar_id': self.test_company.resource_calendar_id.id,
+            'date_from': leave_start_datetime,
+            'date_to': leave_end_datetime,
+        })
+
+        # 5 Timesheets should have been created for full_time_employee and full_time_employee_2
+        # but none for part_time_employee
+        leave_task = self.test_company.leave_timesheet_task_id
+
+        # Now we delete the calendar_id. The timesheets should be deleted too.
+        global_time_off.calendar_id = False
+
+        self.assertFalse(leave_task.timesheet_ids.ids)
+
+        # Now we reset the calendar_id. The timesheets should be created and have the right value.
+        global_time_off.calendar_id = self.test_company.resource_calendar_id.id
+
+        timesheets_by_employee = defaultdict(lambda: self.env['account.analytic.line'])
+        for timesheet in leave_task.timesheet_ids:
+            timesheets_by_employee[timesheet.employee_id] |= timesheet
+        self.assertFalse(timesheets_by_employee.get(self.part_time_employee, False))
+        self.assertEqual(len(timesheets_by_employee.get(self.full_time_employee)), 5)
+        self.assertEqual(len(timesheets_by_employee.get(self.full_time_employee_2)), 5)
+
+        # The standard calendar is for 8 hours/day from 8 to 12 and from 13 to 17.
+        # So we need to check that the timesheets don't have more than 8 hours per day.
+        self.assertEqual(leave_task.effective_hours, 80)