[FIX] resource,hr_payroll: disable timezone conversion

In the case of calculating payroll, we don't want to convert the
datetimes using the timezone of the user as we really want to see what
the employee has done from one date to another (usually from the start of
the month to end of the month)

Closes #26256

closes odoo/odoo#28977

addons/hr_payroll/models/hr_payslip.py

@@ -194,7 +194,7 @@ class HrPayslip(models.Model):
                         current_leave_struct['number_of_days'] += leave_time / work_hours
 
             # compute worked days
-            work_data = contract.employee_id.get_work_days_data(day_from, day_to, calendar=contract.resource_calendar_id)
+            work_data = contract.employee_id.with_context(no_tz_convert=True).get_work_days_data(day_from, day_to, calendar=contract.resource_calendar_id)
             attendances = {
                 'name': _("Normal Working Days paid at 100%"),
                 'sequence': 1,

addons/resource/models/resource.py

@@ -417,8 +417,9 @@ class ResourceCalendar(models.Model):
         if not end_dt:
             end_dt = datetime.datetime.combine(start_dt.date(), datetime.time.max)
 
-        start_dt = to_naive_user_tz(start_dt, self.env.user)
-        end_dt = to_naive_user_tz(end_dt, self.env.user)
+        if not self.env.context.get('no_tz_convert', False):
+            start_dt = to_naive_user_tz(start_dt, self.env.user)
+            end_dt = to_naive_user_tz(end_dt, self.env.user)
 
         for day in rrule.rrule(rrule.DAILY,
                                dtstart=start_dt,

addons/resource/models/resource_mixin.py

@@ -51,6 +51,7 @@ class ResourceMixin(models.AbstractModel):
         days_count = 0.0
         total_work_time = timedelta()
         calendar = calendar or self.resource_calendar_id
+        calendar = calendar.with_context(no_tz_convert=self.env.context.get('no_tz_convert', False))
         for day_intervals in calendar._iter_work_intervals(
                 from_datetime, to_datetime, self.resource_id.id,
                 compute_leaves=True):