diff --git a/main/forum/forumfunction.inc.php b/main/forum/forumfunction.inc.php
index 2a0a307eb1..f6f81c0e4a 100755
--- a/main/forum/forumfunction.inc.php
+++ b/main/forum/forumfunction.inc.php
@@ -718,8 +718,8 @@ function store_forum($values, $courseInfo = array(), $returnId = false)
             'forum_of_group'=> isset($values['group_forum']) ? $values['group_forum'] : null,
             'forum_group_public_private'=> isset($values['public_private_group_forum_group']['public_private_group_forum']) ? $values['public_private_group_forum_group']['public_private_group_forum'] : null,
             'moderated'=> isset($values['moderated']['moderated']) ? 1 : 0,
-            'start_time' => isset($values['start_time']) ? api_get_utc_datetime($values['start_time']) : null,
-            'end_time' => isset($values['end_time']) ? api_get_utc_datetime($values['end_time']) : null,
+            'start_time' => !empty($values['start_time']) ? api_get_utc_datetime($values['start_time']) : null,
+            'end_time' => !empty($values['end_time']) ? api_get_utc_datetime($values['end_time']) : null,
             'forum_order'=> isset($new_max) ? $new_max : null,
             'session_id'=> $session_id,
             'lp_id' => isset($values['lp_id']) ? intval($values['lp_id']) : 0
@@ -761,8 +761,8 @@ function store_forum($values, $courseInfo = array(), $returnId = false)
             'forum_of_group'=> isset($values['group_forum']) ? $values['group_forum'] : null,
             'forum_group_public_private'=> isset($values['public_private_group_forum_group']['public_private_group_forum']) ? $values['public_private_group_forum_group']['public_private_group_forum'] : null,
             'moderated'=> isset($values['moderated']['moderated']) ? 1 : 0,
-            'start_time' => isset($values['start_time']) ? api_get_utc_datetime($values['start_time']) : null,
-            'end_time' => isset($values['end_time']) ? api_get_utc_datetime($values['end_time']) : null,
+            'start_time' => !empty($values['start_time']) ? api_get_utc_datetime($values['start_time']) : null,
+            'end_time' => !empty($values['end_time']) ? api_get_utc_datetime($values['end_time']) : null,
             'forum_order'=> isset($new_max) ? $new_max : null,
             'session_id'=> $session_id,
             'lp_id' => isset($values['lp_id']) ? intval($values['lp_id']) : 0,