linux modify time zone

[root@fxqtest ~]# date -R
Mon, 23 Apr 2018 02:03:30 -0700
[root@fxqtest ~]# ll /etc/localtime
-rw-r--r--. 1 root root 2819 Apr 23 00:52 /etc/localtime
[root@fxqtest ~]# cp /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
cp: overwrite `/etc/localtime'? y
[root@fxqtest ~]# date -R
Mon, 23 Apr 2018 17:03:52 +0800
[root@fxqtest ~]#