diff --git a/addons/point_of_sale/point_of_sale.py b/addons/point_of_sale/point_of_sale.py
index 46bc3e92c41..8bee8a4245c 100644
--- a/addons/point_of_sale/point_of_sale.py
+++ b/addons/point_of_sale/point_of_sale.py
@@ -305,7 +305,7 @@ class pos_order(osv.osv):
         'state': 'draft',
         'price_type': 'tax_excluded',
         'name': lambda obj, cr, uid, context: obj.pool.get('ir.sequence').get(cr, uid, 'pos.order'),
-        'date_order': time.strftime('%Y-%m-%d %H:%M:%S'),
+        'date_order': lambda *a: time.strftime('%Y-%m-%d %H:%M:%S'),
         'date_validity': lambda *a: (datetime.today() + relativedelta(months=+6)).strftime('%Y-%m-%d'),
         'nb_print': 0,
         'company_id': lambda self,cr,uid,c: self.pool.get('res.users').browse(cr, uid, uid, c).company_id.id,
diff --git a/addons/point_of_sale/wizard/pos_details.py b/addons/point_of_sale/wizard/pos_details.py
index a710692a37a..8a63ae97dbd 100644
--- a/addons/point_of_sale/wizard/pos_details.py
+++ b/addons/point_of_sale/wizard/pos_details.py
@@ -32,8 +32,8 @@ class pos_details(osv.osv_memory):
         'date_end': fields.date('Date End', required=True)
     }
     _defaults = {
-        'date_start': time.strftime('%Y-%m-%d'),
-        'date_end': time.strftime('%Y-%m-%d'),
+        'date_start': lambda *a: time.strftime('%Y-%m-%d'),
+        'date_end': lambda *a: time.strftime('%Y-%m-%d'),
     }
 
     def print_report(self, cr, uid, ids, context=None):
diff --git a/addons/point_of_sale/wizard/pos_payment_report_date.py b/addons/point_of_sale/wizard/pos_payment_report_date.py
index f2e3fb40419..49e21c01c05 100644
--- a/addons/point_of_sale/wizard/pos_payment_report_date.py
+++ b/addons/point_of_sale/wizard/pos_payment_report_date.py
@@ -57,8 +57,8 @@ class pos_payment_report_date(osv.osv_memory):
         'user_id': fields.many2many('res.users', 'res_user_sale', 'user_id', 'sale_id', 'Salesman')
     }
     _defaults = {
-        'date_start': time.strftime('%Y-%m-%d'),
-        'date_end': time.strftime('%Y-%m-%d'),
+        'date_start': lambda *a: time.strftime('%Y-%m-%d'),
+        'date_end': lambda *a: time.strftime('%Y-%m-%d'),
     }
 
 pos_payment_report_date()
diff --git a/addons/sale/sale.py b/addons/sale/sale.py
index 5bbd6d5d799..d00576e7c07 100644
--- a/addons/sale/sale.py
+++ b/addons/sale/sale.py
@@ -286,7 +286,7 @@ class sale_order(osv.osv):
     }
     _defaults = {
         'picking_policy': 'direct',
-        'date_order': time.strftime('%Y-%m-%d'),
+        'date_order': lambda *a: time.strftime('%Y-%m-%d'),
         'order_policy': 'manual',
         'state': 'draft',
         'user_id': lambda obj, cr, uid, context: uid,