To see current timezone, run

root@server20 [~]# timedatectl status
      Local time: Sat 2015-10-24 03:46:18 UTC
  Universal time: Sat 2015-10-24 03:46:18 UTC
        RTC time: Sat 2015-10-24 03:46:14
        Timezone: UTC (UTC, +0000)
     NTP enabled: n/a
NTP synchronized: no
 RTC in local TZ: no
      DST active: n/a
root@server20 [~]# 

To set timezone to UTC, run

timedatectl set-timezone UTC

To See all available timezones, run

timedatectl list-timezones