Here is a guide on how to change the timezone via terminal in linux.
1. Log in as root, check which timezone your machine is currently using by executing `date`. You’ll see something like:
Mon 17 Jan 2005 12:15:08 PM PST, PST in this case is the current timezone.
2. Change to the directory /usr/share/zoneinfo here you will find a list of time zone regions. Choose the most appropriate region, if you live in Canada or the US this directory is the “America” directory.
3. If you wish, backup the previous timezone configuration by copying it to a different location. Such as
mv /etc/localtime /etc/localtime-old
4. Create a symbolic link to the appropriate timezone from /etc/localtime. Example:
ln -sf /usr/share/zoneinfo/Europe/Amsterdam /etc/localtime
5. If you have the utility rdate, update the current system time by executing
/usr/bin/rdate -s time-a.nist.gov
6. Set the ZONE entry in the file /etc/sysconfig/clock file (e.g. “America/Los_Angeles”)
7. Set the hardware clock by executing:
This guide is from the link http://www.wikihow.com/Change-the-Timezone-in-Linux