To change the time zone in Linux, using the command line just enter this commands, do not worry they are few and easy.

cd /usr/share/zoneinfo

Look for your city, in my case it is:

America/La_Paz

Now create a link to the file /etc/localtime by doing this:

sudo ln -sf /usr/share/zoneinfo/America/La_Paz /etc/localtime

And you are done.