diff --git a/htdocs/public/eventorganization/attendee_subscription.php b/htdocs/public/eventorganization/attendee_subscription.php
index b477d644dc7..9f3115e56f4 100644
--- a/htdocs/public/eventorganization/attendee_subscription.php
+++ b/htdocs/public/eventorganization/attendee_subscription.php
@@ -331,7 +331,7 @@ if (empty($reshook) && $action == 'add') {
 			if (!$error) {
 				// Add line to draft invoice
 				$vattouse = get_default_tva($mysoc, $thirdparty, $productforinvoicerow->id);
-				$result = $facture->addline($langs->trans("ConferenceAttendeeFee").' for the event : \''.$conference->label.'\' occuring from '.$conference->datep.' to '.$conference->datep2, floatval($project->price_registration), 1, $vattouse, 0, 0, $productforinvoicerow->id, 0, dol_now(), '', 0, 0, '', 'HT', 0, 1);
+				$result = $facture->addline($langs->trans("ConferenceAttendeeFee").' for the event : \''.$conference->label.'\' occuring from '.dol_print_date($conference->datep, '%d/%m/%y %H:%M:%S').' to '.dol_print_date($conference->datep2, '%d/%m/%y %H:%M:%S'), floatval($project->price_registration), 1, $vattouse, 0, 0, $productforinvoicerow->id, 0, dol_now(), '', 0, 0, '', 'HT', 0, 1);
 				if ($result <= 0) {
 					$confattendee->error = $facture->error;
 					$confattendee->errors = $facture->errors;