You can sync your system time and date with ntp (Network Time Protocol) over a network or internet. Normally ntp should be installed to your Linux system as default, in case your system does not have ntp, you can easily install ntp package with a simple command.
To install ntp on Ubuntu, Linux or debian based distribitions
# apt-get update
# apt-get install ntp
To install ntp on Fedora, Centos or redhat based distribitions
# yum install ntp
After you set your timezone correcly, you should be able to synce your date and time with ntp command
# ntpdate pool.ntp.org