diff --git a/addons/purchase/purchase.py b/addons/purchase/purchase.py
index 4ca0521177c..687221f371b 100644
--- a/addons/purchase/purchase.py
+++ b/addons/purchase/purchase.py
@@ -675,7 +675,7 @@ class purchase_order(osv.osv):
                 # convert datetime field to a datetime, using server format, then
                 # convert it to the user TZ and re-render it with %Z to add the timezone
                 picking_datetime = fields.DT.datetime.strptime(picking.min_date, DEFAULT_SERVER_DATETIME_FORMAT)
-                picking_date_str = fields.datetime.context_timestamp(cr, uid, meeting_datetime, context=context).strftime(DATETIME_FORMATS_MAP['%+'] + " (%Z)")
+                picking_date_str = fields.datetime.context_timestamp(cr, uid, picking_datetime, context=context).strftime(DATETIME_FORMATS_MAP['%+'] + " (%Z)")
                 self.message_append_note(cr, uid, [order.id], body=_("Shipment <em>%s</em> <b>scheduled</b> for %s.") % (picking.name, picking_date_str), context=context)
     
     def invoice_send_note(self, cr, uid, ids, invoice_id, context=None):