this will show you a graphical interface to setup
$ sudo dpkg-reconfigure tzdata
choose US->Central
Current default time zone: 'US/Central' Local time is now: Thu Jan 14 13:27:49 CST 2016. Universal Time is now: Thu Jan 14 19:27:49 UTC 2016.
$ date
Thu Jan 14 13:27:57 CST 2016
to list all timezones
$ timedatectl list-timezones
or you can change the timezone with timedatectl, for EST
$ sudo timedatectl set-timezone EST
for central time
$ sudo timedatectl set-timezone America/Chicago
