Managing Date Time Clocks Server Linux Systems Archives

Setting timezone on CentOS 6

Check current time zone of your Server

#date
Tue Jul 26 21:07:48 BST 2016

On on CentOS 6 the list of time zone files located at /usr/share/zoneinfo.

#cd /usr/share/zoneinfo
#ls -la
drwxr-xr-x. 20 root root  4096 Jul 10  2015 .
drwxr-xr-x. 63 root root  4096 Jul 25 23:56 ..
drwxr-xr-x.  2 root root  4096 Jul 10  2015 Africa
drwxr-xr-x.  6 root root  4096 Jul 10  2015 America
........................................................

Find the time zone for your location and note of the appropriate folder and file, for example: America/Chicago.
First, make a backup of the existing localtime file. It’s always good practice to make backups of original config files.

#mv /etc/localtime /etc/localtime.bak

Then create the link:

#ln -s /usr/share/zoneinfo/America/Chicago /etc/localtime

Now check the change

#date
Tue Jul 26 16:03:18 EDT 2016

Additional task is make sure the settings stay applied after on reboot

#vi /etc/sysconfig/clock

change the zone line to:

ZONE="America/Chicago"

Install Configure NTP to Synchronize Clocks of System on CentOS 6

NTP (Network Time Protocol) is an Internet protocol used to synchronize the clocks of computers to some time reference. NTP is an Internet standard protocol originally developed by Professor David L. Mills at the University of Delaware.

Install and configure NTP (Network Time Protocol)
NTP package is provided by default on CentOS /RHEL 7 repositories and can be installed with command below

#yum install ntp

Turn on service as daemon, start automatically on rebooot

#chkconfig ntpd on

Start the NTP server, NTP will continuously adjusts system time from upstream NTP server

#/etc/init.d/ntpd start