Logged 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.
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.
If you wish, backup the previous timezone configuration by copying it to a different location. Such as
mv /etc/localtime /etc/localtime-old
Create a symbolic link to the appropriate timezone from /etc/localtime. Example: