How to update ntp server in CENTOS 7-8?

Managing System Time and NTP in Linux

Keeping your server’s time accurate is crucial — whether it’s for logging, cron jobs, or secure connections. Here’s a quick guide to checking and setting time on a Linux system, along with enabling NTP for automatic synchronization.

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🔍 Check the Current Time

Check the hardware clock (BIOS/RTC):

hwclock

Check the system clock (software):

timedatectl

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⏱ Enable NTP (Network Time Protocol)

To let your system automatically sync with time servers, enable NTP:

timedatectl set-ntp yes

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🕒 Manually Set the Time

If you need to set the time manually (e.g., no NTP available):

timedatectl set-time HH:MM:SS

(Replace HH:MM:SS with your desired time.)

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⚙️ Start and Enable NTP Daemon

For continuous synchronization with NTP servers, start and enable the ntpd service:

sudo systemctl start ntpd
sudo systemctl enable ntpd

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🌍 Sync with a Specific NTP Server

You can manually sync your system clock to a specific NTP server and then update the hardware clock:

ntpdate -u clock.ncbs.res.in && hwclock -w

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✅ That’s it! Now your Linux system should stay in sync with accurate time.