Set timezone in Redhat Linux 7

[root@hdp30 ~]# timedatectl list-timezones|grep -i singapore
Asia/Singapore

[root@hdp30 ~]# timedatectl
      Local time: Sat 2018-08-04 00:56:47 UTC
  Universal time: Sat 2018-08-04 00:56:47 UTC
        RTC time: Sat 2018-08-04 00:56:47
       Time zone: Etc/UTC (UTC, +0000)
     NTP enabled: yes
NTP synchronized: yes
 RTC in local TZ: no
      DST active: n/a


[root@hdp30 ~]# timedatectl set-timezone Asia/Singapore

[root@hdp30 ~]# timedatectl
      Local time: Sat 2018-08-04 08:58:21 +08
  Universal time: Sat 2018-08-04 00:58:21 UTC
        RTC time: Sat 2018-08-04 00:58:22
       Time zone: Asia/Singapore (+08, +0800)
     NTP enabled: yes
NTP synchronized: yes
 RTC in local TZ: no
      DST active: n/a