By default, Ubuntu Linux ensures your computer’s clock is always perfectly accurate by automatically synchronizing it with atomic time servers over the internet using the Network Time Protocol (NTP). A background daemon (usually systemd-timesyncd) periodically pings servers like pool.ntp.org and silently corrects your system time if it starts to drift.
While this is desirable for 99% of users, there are highly specific edge cases where you absolutely must prevent the clock from changing automatically. If you are running an isolated server network without internet access, testing time-sensitive cryptographic certificates, or deliberately manipulating the system clock to debug legacy software, an automatic NTP synchronization will instantly ruin your test environment by aggressively overriding your manual time settings.
You can easily disable the NTP daemon directly from the command line, giving you total, manual control over the system clock.
How to Turn Off NTP Time Synchronization in Ubuntu
You must use the timedatectl command to manage the system clock behavior.
- Open your terminal application (
Ctrl+Alt+T) or SSH into your Ubuntu server. - First, check the current status of the time synchronization daemon by running:
timedatectl status - Look for the line that says
NTP service: active. - To permanently disable the automatic synchronization, run the following command (you will need sudo privileges):
sudo timedatectl set-ntp off - Verify that the daemon is disabled by running
timedatectl statusagain. It should now readNTP service: inactive.
Ubuntu will immediately stop pinging external servers for the time. Your system clock is now entirely isolated and static. It will only progress based on the hardware real-time clock (RTC), and it will only accept manual time changes initiated by you.