Changing Timezone in linux.
1) Change to the directory /usr/share/zoneinfo, where you can find list of timezone regions
2) Move your existing time zone
mv /etc/localtime /etc/localtime-old
3) Link the timezone u needed to localtime
ln -sf /usr/share/zoneinfo/America/Pacific /etc/localtime
4) Update the system time by
/usr/bin/rdate -s time-a.nist.gov
5) Set the ZONE entry in the file /etc/sysconfig/clock file (e.g. "America/Los_Angeles")
6) /sbin/hwclock --systohc
