diff --git a/htdocs/webservices/server_invoice.php b/htdocs/webservices/server_invoice.php
index c79c862146c..c59544aa3f8 100644
--- a/htdocs/webservices/server_invoice.php
+++ b/htdocs/webservices/server_invoice.php
@@ -537,6 +537,8 @@ function createInvoice($authentication,$invoice)
             $newline->total_ht=$line['total_net'];
             $newline->total_tva=$line['total_vat'];
             $newline->total_ttc=$line['total'];
+            $newline->date_start=dol_stringtotime($line['date_start']);
+            $newline->date_end=dol_stringtotime($line['date_end']);
             $newline->fk_product=$line['product_id'];
             $newobject->lines[]=$newline;
         }