Timekeeping¶
systemd-timesyncd.service¶
Systemd has introduced their own SNTP implementation called timesyncd. Timesyncd only implements a subset of the NTP protocol, which is why it's called SNTP. It has been used since Debian "bookworm", and by extension, Ubuntu (which is downstream of Debian).
timedatectl¶
This is a command that can be used to view the current status of time synchronization.
Text Only
$ timedatectl timesync-status
Server: 91.189.91.157 (ntp.ubuntu.com)
Poll interval: 34min 8s (min: 32s; max 34min 8s)
Leap: normal
Version: 4
Stratum: 2
Reference: 84A36001
Precision: 1us (-24)
Root distance: 24.421ms (max: 5s)
Offset: -15.315ms
Delay: 48.943ms
Jitter: 10.320ms
Packet count: 9
Frequency: -23.604ppm
chrony¶
chrony implements the full NTP protocol and is often a replacement for timesyncd. A comparison of chrony against other implementations can be found here.
ntp¶
This is the reference implementation.