diff --git a/addons/purchase_requisition/wizard/purchase_requisition_partner.py b/addons/purchase_requisition/wizard/purchase_requisition_partner.py
index 2ae3ae795e9..f32e8331784 100644
--- a/addons/purchase_requisition/wizard/purchase_requisition_partner.py
+++ b/addons/purchase_requisition/wizard/purchase_requisition_partner.py
@@ -86,14 +86,19 @@ class purchase_requisition_partner(osv.osv_memory):
                     uom_id = line.product_id.uom_po_id and line.product_id.uom_po_id.id or False
                     newdate = datetime.strptime(tender.date_start, '%Y-%m-%d %H:%M:%S')
                     newdate = newdate - relativedelta(days=company.po_lead)
-                    delay = partner_rec and partner_rec.delay or False
-                    newdate = newdate -(delay or datetime.strptime(tender.date_start, '%Y-%m-%d %H:%M:%S') )
+                    delay = partner_rec and partner_rec.delay or 0.0
+                    newdate = newdate -(delay and relativedelta(days=delay) or datetime.strptime(tender.date_start, '%Y-%m-%d %H:%M:%S') )
                     partner = partner_rec and partner_rec.name or supplier_data
                     pricelist_id = partner.property_product_pricelist_purchase and partner.property_product_pricelist_purchase.id or False
                     price = pricelist_obj.price_get(cr, uid, [pricelist_id], line.product_id.id, line.product_qty, False, {'uom': uom_id})[pricelist_id]
                     product = prod_obj.browse(cr, uid, line.product_id.id, context=context)
                     location_id = self.pool.get('stock.warehouse').read(cr, uid, [tender.warehouse_id.id], ['lot_input_id'])[0]['lot_input_id'][0]
 
+                    if not newdate:
+                        date_planned = datetime.strptime(tender.date_start, '%Y-%m-%d %H:%M:%S')
+                    else:
+                        date_planned = newdate.strftime('%Y-%m-%d %H:%M:%S')
+
                     purchase_order_line= {
                             'name': product.partner_ref,
                             'product_qty': line.product_qty,