Use key2=”client_action_multi” in act_window to add submenu to “Action” button (“More” in previous Odoo versions). Reference here <act_window name=”New Sub menu” res_model=”product.product” src_model=”product.product” key2=”client_action_multi” view_mode=”form” target=”new” view_type=”form” id=”act_new_sub_menu” /> solved How to add a button to the Action menu?
Try with this example: from dateutil.relativedelta import relativedelta @api.one @api.depends(‘start_field’,’finish_field’) def _total_minutes(self): if self.start_field and self.finish_field: start_dt = fields.Datetime.from_string(self.start_field) finish_dt = fields.Datetime.from_string(self.finish_field) difference = relativedelta(finish_dt, start_dt) days = difference.days hours = difference.hours minutes = difference.minutes seconds = 0 1 solved Calculate difference between two datetimes odoo 10 [duplicate]