Maintaining accurate system clocks is crucial to supporting your infrastructure. Being able to pinpoint timing of issues in logs using accurately across your environment is key. Fortunately there are some tools available at your disposal to make this easy in CentOS.
NTP – Running ntpd the ntp daemon will ensure your clocks are in sync with the ntp servers configured in /etc/ntp.conf.
Timezones – Making sure all systems are using the same timezone is helpful as well.(Comments)