How to Change the Timezone in Linux?
Most modern Linux distributions have user-friendly programs to set the timezone, often accessible through the program menus or right-clicking the clock in a desktop environment such as KDE or GNOME. Failing that it’s possible to manually change the system timezone in Linux in a few short steps.
1. Logged in as root. Check which timezone your machine is currently using by executing `date`:
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. For example if you live in Canada or the US this directory is the “America” directory.
3. If you wish, backup the previous timezone configuration by renaming it:
# mv /etc/localtime /etc/localtime.old
4. Create a symbolic link to the appropriate timezone from /etc/localtime. Example:
# ln -sf /usr/share/zoneinfo/Asia/Tehran /etc/localtime
5. Set the TIMEZONE, HWCLOCK entries in the file /etc/sysconfig/clock file to the appropriate values:
TIMEZONE="Asia/Tehran" HWCLOCK="--localtime"
6. Set the hardware clock:
# hwclock --localtime
Reference: How to Change the Timezone in Linux
