diff --git a/main/metadata/phpdig/phpdig_functions.php b/main/metadata/phpdig/phpdig_functions.php
index 634a837681..515ec7d384 100755
--- a/main/metadata/phpdig/phpdig_functions.php
+++ b/main/metadata/phpdig/phpdig_functions.php
@@ -268,8 +268,9 @@ function phpdigAddLog ($id_connect,$option='start',$includes=array(),$excludes=a
          $includes = array();
     }
     sort($includes);
+    $now = api_get_utc_datetime();
     $query = 'INSERT INTO '.PHPDIG_DB_PREFIX.'logs (l_num,l_mode,l_ts,l_includes,l_excludes,l_time) '
-             .'VALUES ('.$num_results.',\''.substr($option,0,1).'\',NOW(),'
+             .'VALUES ('.$num_results.',\''.substr($option,0,1).'\',"' . $now . '",'
              .'\''.implode(' ',$includes).'\',\''.implode(' ',$excludes).'\','.(double)$time.')';
     mysql_query($query,$id_connect);
     return mysql_insert_id($id_connect);
diff --git a/main/newscorm/lp_comm.server.php b/main/newscorm/lp_comm.server.php
index 1b26e2a352..be3941f13a 100755
--- a/main/newscorm/lp_comm.server.php
+++ b/main/newscorm/lp_comm.server.php
@@ -152,7 +152,8 @@ function save_item($lp_id, $user_id, $view_id, $item_id, $score = -1, $max = -1,
         if (Database::num_rows($q_last_connection) > 0) {
             $row = Database::fetch_array($q_last_connection);
             $i_id_last_connection = $row['login_id'];
-            $s_sql_update_logout_date = "UPDATE $tbl_track_login SET logout_date=NOW() WHERE login_id='$i_id_last_connection'";
+            $now = api_get_utc_datetime();
+            $s_sql_update_logout_date = "UPDATE $tbl_track_login SET logout_date = '$now' WHERE login_id='$i_id_last_connection'";
             Database::query($s_sql_update_logout_date);
         }
 
diff --git a/main/tracking/personnalLog.php b/main/tracking/personnalLog.php
index 479ea71487..f8e62f78f4 100755
--- a/main/tracking/personnalLog.php
+++ b/main/tracking/personnalLog.php
@@ -115,9 +115,8 @@ api_display_tool_title($nameTools);
         </td>
     </tr>";
 
-                if(!isset($previousDate)) {
-                    $sql = "SELECT NOW()";
-                    $previousDate = StatsUtils::getOneResult($sql);
+                if (!isset($previousDate)) {
+                    $previousDate = api_get_utc_datetime();
                 }
 
                 $sql = "SELECT access_tool, count(access_tool), c_id
diff --git a/main/tracking/userLog.php b/main/tracking/userLog.php
index d56d99f795..d2c0929306 100755
--- a/main/tracking/userLog.php
+++ b/main/tracking/userLog.php
@@ -71,13 +71,14 @@ $TABLEUSER	        		= Database::get_main_table(TABLE_MAIN_USER);
 $tbl_session_course_user 	= Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
 $tbl_session 				= Database::get_main_table(TABLE_MAIN_SESSION);
 $TABLECOURSE_GROUPSUSER 	= Database::get_course_table(TABLE_GROUP_USER);
+$now = api_get_utc_datetime();
 
 $sql = "SELECT 1
         FROM $tbl_session_course_user AS session_course_user
         INNER JOIN $tbl_session AS session
             ON session_course_user.id_session = session.id
-            AND ((date_start<=NOW()
-            AND date_end>=NOW())
+            AND ((date_start <= '$now'
+            AND date_end >= '$now')
             OR (date_start='0000-00-00' AND date_end='0000-00-00'))
         WHERE id_session='".api_get_session_id()."' AND course_code='$_cid'";
 //echo $sql;
diff --git a/main/tracking/userlogCSV.php b/main/tracking/userlogCSV.php
index 06b0a2cf41..1b2289918b 100755
--- a/main/tracking/userlogCSV.php
+++ b/main/tracking/userlogCSV.php
@@ -73,13 +73,14 @@ $tbl_session_course_user = Database::get_main_table(
 $tbl_session = Database::get_main_table(TABLE_MAIN_SESSION);
 
 $TABLECOURSE_GROUPSUSER = Database::get_course_table(TABLE_GROUP_USER);
+$now = api_get_utc_datetime();
 
 $sql = "SELECT 1
         FROM $tbl_session_course_user AS session_course_user
         INNER JOIN $tbl_session AS session
             ON session_course_user.id_session = session.id
-            AND ((date_start<=NOW()
-            AND date_end>=NOW())
+            AND ((date_start <= '$now'
+            AND date_end >= '$now')
             OR (date_start='0000-00-00' AND date_end='0000-00-00'))
         WHERE id_session='" . $_SESSION['id_session'] . "' AND course_code='$_cid'";
 //echo $sql;