whatsapp_web_groups/custom_project/models/project_task.py

# -*- coding: utf-8 -*-

from odoo import models, fields, api
from datetime import datetime, timedelta

class ProjectTask(models.Model):
    _inherit = "project.task"

    x_start_date = fields.Date(string="Fecha inicio")
    x_end_date = fields.Date(string="Fecha final")

    @api.depends('date_deadline', 'planned_date_begin', 'user_ids')
    def _compute_allocated_hours(self):
        for rec in self:
            rec.allocated_hours = 0

    @api.onchange("x_start_date")
    def onchange_start_date(self):
        for rec in self:
            if rec.x_start_date:
                rec.planned_date_begin = datetime.combine(rec.x_start_date, datetime.min.time()) + timedelta(hours=9)

    @api.onchange("x_end_date")
    def onchange_end_date(self):
        for rec in self:
            if rec.x_end_date:
                rec.date_deadline = datetime.combine(rec.x_end_date, datetime.min.time()) + timedelta(hours=9)