diff --git a/htdocs/install/mysql/migration/16.0.0-17.0.0.sql b/htdocs/install/mysql/migration/16.0.0-17.0.0.sql
index 044d97fd4e4..f1b29472d06 100644
--- a/htdocs/install/mysql/migration/16.0.0-17.0.0.sql
+++ b/htdocs/install/mysql/migration/16.0.0-17.0.0.sql
@@ -384,3 +384,5 @@ ALTER TABLE llx_prelevement_demande ADD COLUMN fk_salary INTEGER NULL AFTER fk_f
 
 
 ALTER TABLE llx_user ADD COLUMN birth_place varchar(64);
+ALTER TABLE llx_opensurvey_user_studs ADD COLUMN date_creation datetime NOT NULL;
+ALTER TABLE llx_opensurvey_comments ADD COLUMN date_creation datetime NOT NULL;
\ No newline at end of file
diff --git a/htdocs/install/mysql/tables/llx_opensurvey_comments-opensurvey.sql b/htdocs/install/mysql/tables/llx_opensurvey_comments-opensurvey.sql
index 52d938b7c47..a615e0f9cb7 100644
--- a/htdocs/install/mysql/tables/llx_opensurvey_comments-opensurvey.sql
+++ b/htdocs/install/mysql/tables/llx_opensurvey_comments-opensurvey.sql
@@ -21,5 +21,6 @@ CREATE TABLE llx_opensurvey_comments (
     comment text NOT NULL,
     tms timestamp DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
     usercomment text
+    date_creation datetime NOT NULL, 
 ) ENGINE=innodb;
 
diff --git a/htdocs/install/mysql/tables/llx_opensurvey_user_studs-opensurvey.sql b/htdocs/install/mysql/tables/llx_opensurvey_user_studs-opensurvey.sql
index 03ad9b35ec5..d0d1c2a06b8 100644
--- a/htdocs/install/mysql/tables/llx_opensurvey_user_studs-opensurvey.sql
+++ b/htdocs/install/mysql/tables/llx_opensurvey_user_studs-opensurvey.sql
@@ -21,4 +21,5 @@ CREATE TABLE llx_opensurvey_user_studs (
     id_sondage VARCHAR(16) NOT NULL,
     reponses VARCHAR(100) NOT NULL,		-- Not used for 'F' surveys
     tms timestamp DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
+    date_creation datetime NOT NULL, 
 ) ENGINE=innodb;
diff --git a/htdocs/opensurvey/class/opensurveysondage.class.php b/htdocs/opensurvey/class/opensurveysondage.class.php
index b7fadbdb60d..4d67c9a3a95 100644
--- a/htdocs/opensurvey/class/opensurveysondage.class.php
+++ b/htdocs/opensurvey/class/opensurveysondage.class.php
@@ -576,8 +576,9 @@ class Opensurveysondage extends CommonObject
 	 */
 	public function addComment($comment, $comment_user, $user_ip = '')
 	{
-		$sql = "INSERT INTO ".MAIN_DB_PREFIX."opensurvey_comments (id_sondage, comment, usercomment, ip)";
-		$sql .= " VALUES ('".$this->db->escape($this->id_sondage)."','".$this->db->escape($comment)."','".$this->db->escape($comment_user)."'".($user_ip ? ",'".$this->db->escape($user_ip)."'" : '').")";
+		$now = dol_now();
+		$sql = "INSERT INTO ".MAIN_DB_PREFIX."opensurvey_comments (id_sondage, comment, usercomment, date_creation, ip)";
+		$sql .= " VALUES ('".$this->db->escape($this->id_sondage)."','".$this->db->escape($comment)."','".$this->db->escape($comment_user)."','".$this->db->idate($now)."'".($user_ip ? ",'".$this->db->escape($user_ip)."'" : '').")";
 		$resql = $this->db->query($sql);
 
 		if (!$resql) {
diff --git a/htdocs/public/opensurvey/studs.php b/htdocs/public/opensurvey/studs.php
index 30ed4cc8bbb..de2f6b1e3aa 100644
--- a/htdocs/public/opensurvey/studs.php
+++ b/htdocs/public/opensurvey/studs.php
@@ -108,7 +108,7 @@ if (GETPOST('ajoutcomment', 'alpha')) {
 		$sql = "SELECT COUNT(id_comment) as nb_comments";
 		$sql .= " FROM ".MAIN_DB_PREFIX."opensurvey_comments";
 		$sql .= " WHERE ip = '".$db->escape($user_ip)."'";
-		//$sql .= " AND date_creation > '".$db->idate($minmonthpost)."'";
+		$sql .= " AND date_creation > '".$db->idate($minmonthpost)."'";
 		$resql = $db->query($sql);
 		if ($resql) {
 			$num = $db->num_rows($resql);
@@ -164,7 +164,7 @@ if (GETPOST("boutonp") || GETPOST("boutonp.x") || GETPOST("boutonp_x")) {		// bo
 			$sql = "SELECT COUNT(id_users) as nb_records";
 			$sql .= " FROM ".MAIN_DB_PREFIX."opensurvey_user_studs";
 			$sql .= " WHERE ip = '".$db->escape($user_ip)."'";
-			//$sql .= " AND date_creation > '".$db->idate($minmonthpost)."'";
+			$sql .= " AND date_creation > '".$db->idate($minmonthpost)."'";
 			$resql = $db->query($sql);
 			if ($resql) {
 				$num = $db->num_rows($resql);
@@ -198,8 +198,9 @@ if (GETPOST("boutonp") || GETPOST("boutonp.x") || GETPOST("boutonp_x")) {		// bo
 			setEventMessages($langs->trans("AlreadyTooMuchPostOnThisIPAdress"), null, 'errors');
 			$error++;
 		} else {
-			$sql = 'INSERT INTO '.MAIN_DB_PREFIX.'opensurvey_user_studs (nom, id_sondage, reponses, ip)';
-			$sql .= " VALUES ('".$db->escape($nom)."', '".$db->escape($numsondage)."','".$db->escape($nouveauchoix)."', '".$db->escape($user_ip)."')";
+			$now = dol_now();
+			$sql = 'INSERT INTO '.MAIN_DB_PREFIX.'opensurvey_user_studs (nom, id_sondage, reponses, ip, date_creation)';
+			$sql .= " VALUES ('".$db->escape($nom)."', '".$db->escape($numsondage)."','".$db->escape($nouveauchoix)."', '".$db->escape($user_ip)."', '".$db->idate($now)."')";
 			$resql = $db->query($sql);
 
 			if ($resql) {