Installing NTP Service and change timezone in CentOS 6 / CentOS 7

Let’s install NTP service first:

yum install ntp

Configure NTP services by updating the following section (only if appropriate):

nano /etc/ntp.conf

And by commenting on the sections:

# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
#server 0.centos.pool.ntp.org iburst
#server 1.centos.pool.ntp.org iburst
#server 2.centos.pool.ntp.org iburst
#server 3.centos.pool.ntp.org iburst

In my case I used the following National Time Server of Bangladesh:

server bsti1.time.gov.bd
server bsti2.time.gov.bd

save and restart the ntp service.

Change Timezone on a CentOS 6 and 7

How do I see the current time zone on CentOS Linux?

Type the date command or the ls command:

$ date
$ ls -l /etc/localtime

Another option is to type the following command on systemd based distro such as CentOS 7 to see timezone along with the grep command and timedatectl command:

timedatectl
timedatectl | grep -i 'time zone'
date

Change the current timezone in CentOS 7

To find list of all available time zones, run:

# timedatectl list-timezones

##*** Grep possible Asian timezones ***##

# timedatectl list-timezones | grep Asia

Sample outputs:

Africa/Abidjan
Africa/Accra
Africa/Addis_Ababa
Africa/Algiers
Africa/Asmara
Africa/Bamako
Africa/Bangui
Africa/Banjul
....
..
America/Dawson
America/Dawson_Creek
America/Denver
America/Detroit
America/Dominica
America/Edmonton
America/Eirunepe
America/El_Salvador
America/Fortaleza
America/Glace_Bay
....
..
Pacific/Saipan
Pacific/Tahiti
Pacific/Tarawa
Pacific/Tongatapu
Pacific/Wake
Pacific/Wallis

The syntax is as follows to set timezone and need to run as root user:

# timedatectl set-timezone time_zone

In this example, set timezone to America/Chicago

# timedatectl set-timezone America/Chicago

Verify new settings by typing the following two commands:

# date
# ls -l /etc/localtime

Change the current timezone in CentOS 6 and older

You need to use the ln command to set timezone on Centos 6. Type the following commands as root:

cp /etc/localtime /root/old.timezone
rm /etc/localtime
ln -s /usr/share/zoneinfo/America/Chicago /etc/localtime

Verify new settings by typing the following two commands:

date
ls -l /etc/localtime