13.1 About the chronyd Daemon

The chrony package provides a chronyd service daemon and chronyc utility that enable mobile systems and virtual machines to update their system clock after a period of suspension or disconnection from a network.

The chronyd service is primarily designed to allow mobile systems and virtual machines to update their system clock after a period of suspension or disconnection from a network. However, you can also use it to implement a simple NTP client or a NTP server. When used as an NTP server, chronyd can synchronise with higher stratum NTP servers or it can act as a stratum 1 server using time signals received from the Global Positioning System (GPS) or radio broadcasts such as DCF77, MSF, or WWVB.

You can use the chronyc command to manage the chronyd service.

Note

chronyd uses NTP version 3 (RFC 1305), whose features are compatible with NTP version 4 (RFC 5905). However, chronyd does not support several important features of NTP version 4 nor does it support the use of PTP.