diff --git a/session/session.go b/session/session.go
index 51502e0c6e6c5..adae5323ddb48 100644
--- a/session/session.go
+++ b/session/session.go
@@ -1072,13 +1072,14 @@ func CreateSession(store kv.Storage) (Session, error) {
 func loadSystemTZ(se *session) (string, error) {
 	sql := `select variable_value from mysql.tidb where variable_name = "system_tz"`
 	rss, errLoad := se.Execute(context.Background(), sql)
+	defer rss.Close()
 	if errLoad != nil {
 		return "", errLoad
 	}
 	chk := rss[0].NewChunk()
+	defer chk.Close()
 	rss[0].Next(context.Background(), chk)
 	return chk.GetRow(0).GetString(0), nil
-
 }
 
 // BootstrapSession runs the first time when the TiDB server start.
diff --git a/util/timeutil/time.go b/util/timeutil/time.go
index 3b06e153a8412..7dce6f818fd2a 100644
--- a/util/timeutil/time.go
+++ b/util/timeutil/time.go
@@ -1,4 +1,4 @@
-// Copyright 2017 PingCAP, Inc.
+// Copyright 2018 PingCAP, Inc.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -39,7 +39,7 @@ func init() {
 // locCa is a simple cache policy to improve the performance of 'time.LoadLocation'.
 var locCa *locCache
 
-// LocalStr is current TiDB's system timezone name.
+// systemTZ is current TiDB's system timezone name.
 var systemTZ string
 var zoneSources = []string{
 	"/usr/share/zoneinfo/",
@@ -145,8 +145,6 @@ func LoadLocation(name string) (*time.Location, error) {
 
 // Zone returns the current timezone name and timezone offset in seconds.
 // In compatible with MySQL, we change `Local` to `System`.
-// TODO: Golang team plan to return system timezone name intead of
-// returning `Local` when `loc` is `time.Local`. We need keep an eye on this.
 func Zone(loc *time.Location) (string, int64) {
 	_, offset := time.Now().In(loc).Zone()
 	var name string
diff --git a/util/timeutil/time_test.go b/util/timeutil/time_test.go
index 23d52a9da3b36..17cbdf80f1c0c 100644
--- a/util/timeutil/time_test.go
+++ b/util/timeutil/time_test.go
@@ -1,4 +1,4 @@
-// Copyright 2018 The ql Authors. All rights reserved.
+// Copyright 2018 PingCAP, Inc. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSES/QL-LICENSE file.