sudo dpkg-reconfigure tzdata

sudo  timedatectl set-timezone Etc/UTC

ln -fs /usr/share/zoneinfo/UTC /etc/localtime

-rw-r--r-- 1 root root 3661 Mar 13 22:18 /usr/share/zoneinfo/posix/Eire

lrwxrwxrwx 1 root root 13 Mar 13 22:18 /usr/share/zoneinfo/Europe/Dublin -> ../posix/Eire

$ date
Wed Jul 16 22:52:47 EDT 2014

$ cat /etc/timezone
America/New_York

$ sudo dpkg-reconfigure tzdata
$ service cron stop && service cron start

Local time: Mon 2017-07-24 16:32:55 GMT   Universal time: Mon 2017-07-24 16:32:55 UTC
    RTC time: Mon 2017-07-24 16:33:06
    Timezone: GMT (GMT, +0000)
 NTP enabled: yes NTP synchronized: no  RTC in local TZ: no
  DST active: n/a root@bi1:~# timedatectl
  Local time: Mon 2017-07-24 16:33:02 GMT   Universal time: Mon 2017-07-24 16:33:02 UTC
    RTC time: Mon 2017-07-24 16:33:13
    Timezone: GMT (GMT, +0000)
 NTP enabled: yes NTP synchronized: no  RTC in local TZ: no
  DST active: n/a