systemd-timesyncd.service, systemd-timesyncd — Network Time Synchronization
systemd-timesyncd is a system service
that may be used to synchronize the local system clock with a
remote Network Time Protocol server. It also saves the local time
to disk every time the clock has been synchronized and uses this
to possibly advance the system realtime clock on subsequent
reboots to ensure it monotonically advances even if the system
lacks a battery-buffered RTC chip.
specifically implements only SNTP. This minimalistic
service will set the system clock for large offsets or
slowly adjust it for smaller deltas. More complex use
cases are not covered by
The NTP servers contacted are determined from the global
the per-link static settings in
files, and the per-link dynamic settings received over DHCP. See
for more details.
timedatectl(1)'s set-ntp command may be used to enable and start, or disable and stop this service.
timedatectl(1)'s timesync-status or show-timesync command can be used to show the current status of this service.
The modification time of this file indicates the timestamp of the last successful synchronization (or at least the systemd build date, in case synchronization was not possible).
A file that is touched on each successful synchronization, to assist
systemd-time-wait-sync and other applications to detecting synchronization