[IMP] date_conclusion filling when someone sign contract

models/res_partner_contract.py

@@ -12,8 +12,6 @@ class PartnerContract(models.Model):
     )
     date_conclusion = fields.Date(
         string='Date of conclusion',
-        default=datetime.date.today(),
-        required=True
     )
     date_conclusion_fix = fields.Date(
         string='Manual Date of conclusion',
@@ -49,7 +47,7 @@ class PartnerContract(models.Model):
 
     @api.multi
     def action_sign(self):
-        self.write({'state': 'sign'})
+        self.write({'state': 'sign', 'date_conclusion': fields.Date.today()})
 
     @api.multi
     def action_close(self):

views/res_partner_contract.xml

@@ -30,7 +30,7 @@
                 <sheet>
                     <group string="Contract parameters" name="single_params">
                         <field name="name" readonly="1"/>
-                        <field name="create_date"/>
+                        <field name="create_date" readonly="1"/>
                         <field name="date_conclusion" attrs="{'readonly': [('state', 'in', ['sign', 'close'])]}"/>
                         <field name="date_conclusion_fix"/>
                         <field name="partner_id" readonly="1"/>