diff --git a/mod/assignment/lib.php b/mod/assignment/lib.php
index 1a585272c71..fa274b1f82d 100644
--- a/mod/assignment/lib.php
+++ b/mod/assignment/lib.php
@@ -407,21 +407,6 @@ class assignment_base {
     function add_instance($assignment) {
 
         $assignment->timemodified = time();
-        if (empty($assignment->dueenable)) {
-            $assignment->timedue = 0;
-            $assignment->preventlate = 0;
-        } else {
-            $assignment->timedue = make_timestamp($assignment->dueyear, $assignment->duemonth, 
-                                                  $assignment->dueday, $assignment->duehour, 
-                                                  $assignment->dueminute);
-        }
-        if (empty($assignment->availableenable)) {
-            $assignment->timeavailable = 0;
-        } else {
-            $assignment->timeavailable = make_timestamp($assignment->availableyear, $assignment->availablemonth, 
-                                                        $assignment->availableday, $assignment->availablehour, 
-                                                        $assignment->availableminute);
-        }
 
         if ($returnid = insert_record("assignment", $assignment)) {