diff --git a/main/gradebook/gradebook_display_certificate.php b/main/gradebook/gradebook_display_certificate.php
index dd3772f6e8..0d2cdcf34e 100755
--- a/main/gradebook/gradebook_display_certificate.php
+++ b/main/gradebook/gradebook_display_certificate.php
@@ -55,8 +55,7 @@ if (isset($_GET['user_id']) && $_GET['user_id']==strval(intval($_GET['user_id'])
 	?>
 	<tr>
 		<td width="100%" class="actions"><?php echo get_lang('Student').' : '. $value['firstname'].' '.$value['lastname'] ?>
-		</td>
-		
+		</td>		
 	</tr>
 	<tr>
 	<td>
@@ -67,7 +66,7 @@ if (isset($_GET['user_id']) && $_GET['user_id']==strval(intval($_GET['user_id'])
 			?>
 			<tr >
 			<td width="50%"><?php echo get_lang('Score').' : '.$value_certificate['score_certificate'] ?></td>
-			<td width="30%"><?php echo get_lang('Date').' : '.$value_certificate['date_certificate'] ?></td>
+			<td width="30%"><?php echo get_lang('Date').' : '.api_convert_and_format_date($value_certificate['created_at']) ?></td>
 			<td width="20%"><a  onclick="return confirmation();" href="gradebook_display_certificate.php?action=delete&<?php echo 'user_id='.$value_certificate['user_id'].'&amp;cat_id='.$value_certificate['cat_id'] ?>"><?php echo Display::return_icon('delete.gif',get_lang('Delete')); ?></a></td>
 			</tr>
 			<?php
diff --git a/main/gradebook/lib/gradebook_functions.inc.php b/main/gradebook/lib/gradebook_functions.inc.php
index cd638067d3..dbcd5a1048 100755
--- a/main/gradebook/lib/gradebook_functions.inc.php
+++ b/main/gradebook/lib/gradebook_functions.inc.php
@@ -417,7 +417,7 @@ function parse_xml_data($file) {
 	$rs_exist=Database::query($sql_exist,__FILE__,__LINE__);
 	$row=Database::fetch_array($rs_exist);
 	if ($row['count']==0) {
-		$sql='INSERT INTO '.$table_certificate.' (cat_id,user_id,score_certificate,date_certificate)
+		$sql='INSERT INTO '.$table_certificate.' (cat_id,user_id,score_certificate,created_at)
 			  VALUES("'.intval($cat_id).'","'.intval($user_id).'","'.Database::escape_string($score_certificate).'","'.Database::escape_string($date_certificate).'")';
 		$rs=Database::query($sql,__FILE__,__LINE__);  
 	}
@@ -431,10 +431,10 @@ function parse_xml_data($file) {
   */  
   function get_certificate_date_by_user_id ($cat_id,$user_id) {
     	$table_certificate = Database::get_main_table(TABLE_MAIN_GRADEBOOK_CERTIFICATE);
-    	$sql_get_date='SELECT date_certificate FROM '.$table_certificate.' WHERE cat_id="'.intval($cat_id).'" AND user_id="'.intval($user_id).'"';
+    	$sql_get_date='SELECT created_at FROM '.$table_certificate.' WHERE cat_id="'.intval($cat_id).'" AND user_id="'.intval($user_id).'"';
     	$rs_get_date=Database::query($sql_get_date,__FILE__,__LINE__);
     	$row_get_date=Database::fetch_array($rs_get_date,'ASSOC');
-    	return $row_get_date['date_certificate'];
+    	return $row_get_date['created_at'];
   }
   
   /**
@@ -450,7 +450,7 @@ function parse_xml_data($file) {
 	if (!is_null($cat_id) && $cat_id>0) {
   		$sql.=' WHERE cat_id='.Database::escape_string($cat_id);
   	}
-  	$sql.=' ORDER BY u.firstname';
+  	$sql.=' ORDER BY u.firstname';  	
 	$rs=Database::query($sql,__FILE__,__LINE__);
 	$list_users=array();
 	while ($row=Database::fetch_array($rs)) {
@@ -467,11 +467,12 @@ function parse_xml_data($file) {
   */
   function get_list_gradebook_certificates_by_user_id ($user_id,$cat_id=null) {
   	$table_certificate = Database::get_main_table(TABLE_MAIN_GRADEBOOK_CERTIFICATE); 	
-  	$sql='SELECT gc.score_certificate,gc.date_certificate,gc.path_certificate,gc.cat_id,gc.user_id FROM  '.$table_certificate.' gc 
+  	$sql='SELECT gc.score_certificate,gc.created_at,gc.path_certificate,gc.cat_id,gc.user_id FROM  '.$table_certificate.' gc 
 		  WHERE gc.user_id="'.Database::escape_string($user_id).'" ';
 	if (!is_null($cat_id) && $cat_id>0) {
   		$sql.=' AND cat_id='.Database::escape_string($cat_id);
   	}
+
   	$rs = Database::query($sql,__FILE__,__LINE__);
   	$list_certificate=array();
   	while ($row=Database::fetch_array($rs)) {