chrony

Check synchronization status

$ chronyc tracking

$ chronyc sources

$ chronyc sourcestats

$ sudo chronyc makestep

$ chronyc add server [ntp.example.com]

$ chronyc clients

$ chronyc waitsync

chronyc [options] [command]
chronyd [options]

chrony is a versatile NTP (Network Time Protocol) implementation for synchronizing system clocks. It consists of chronyd (daemon) and chronyc (command-line interface).
chrony excels in challenging environments: intermittent network connections, virtual machines with unstable clocks, and systems that sleep or hibernate. It synchronizes faster than ntpd and maintains better accuracy in variable conditions.
Configuration is in /etc/chrony.conf (or /etc/chrony/chrony.conf), specifying NTP servers, access controls, and clock adjustments. The daemon can operate as both NTP client and server.

tracking

Display system clock synchronization status.

Show NTP sources (verbose with -v).

Display source statistics.

Step clock immediately if offset is large.

Add an NTP server.

Remove an NTP source.

Speed up initial synchronization.

Show number of online/offline sources.

Show detailed NTP data for a source.

Wait until synchronized.

-d

Run in foreground (debug mode).

Specify configuration file.

Set clock once and exit.

Like -q but don't set clock.

The makestep command can cause time jumps that affect running applications. Firewall must allow UDP port 123 for NTP. chronyd must run as root or with CAPSYSTIME capability. Some applications may malfunction if time changes significantly.

chrony was originally written by Richard Curnow starting in 1997 to provide better accuracy for systems with intermittent network connectivity. Miroslav Lichvar took over maintenance and development in 2007. chrony has become the default NTP client in many Linux distributions including Fedora and RHEL, chosen over ntpd for its faster sync and better handling of modern computing environments.

ntpd(8), timedatectl(1), hwclock(8)