yum install ntp
chkconfig ntpdate on

add to /etc/ntp/step-tickers
# List of servers used for initial synchronization.
server 0.bg.pool.ntp.org
server 1.bg.pool.ntp.org
server 2.bg.pool.ntp.org
server 3.bg.pool.ntp.org

service ntpdate restart

rm /etc/localtime
ln -s /usr/share/zoneinfo/Europe/Sofia /etc/localtime
/etc/init.d/ntpdate restart
hwclock –systohc