SYSTEMD-TIMESYNCD.SERVICE(8)			     systemd-timesyncd.service

NAME
       systemd-timesyncd.service, systemd-timesyncd - Network Time
       Synchronization

SYNOPSIS
       systemd-timesyncd.service

       /usr/lib/systemd/systemd-timesyncd

DESCRIPTION
       systemd-timesyncd.service is a system service that may be used to
       synchronize the local system clock with a remote Network Time Protocol
       (NTP) 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 (roughly)
       monotonically advances even if the system lacks a battery-buffered RTC
       chip.

       The systemd-timesyncd.service service implements SNTP only. This
       minimalistic service will step the system clock for large offsets or
       slowly adjust it for smaller deltas. Complex use cases that require
       full NTP support (and where SNTP is not sufficient) are not covered by
       systemd-timesyncd.service.

       The NTP servers contacted are determined from the global settings in
       timesyncd.conf(5), the per-link static settings in .network files, and
       the per-link dynamic settings received over DHCP. See
       systemd.network(5) for further 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.

       Initialization of systemd-timesyncd.service delays the start of units
       that are ordered after time-set.target (see systemd.special(7) for
       details) until the local time has been updated from
       /var/lib/systemd/timesync/clock (see below) in order to make it roughly
       monotonic. It does not delay other units until synchronization with an
       accurate reference time sources has been reached. Use systemd-time-
       wait-sync.service(8) to achieve that, which will delay start of units
       that are ordered after time-sync.target until synchronization to an
       accurate reference clock is reached.

       systemd and systemd-timesyncd advance the system clock to the "epoch"
       (the lowest date above which the system clock time is assumed to be set
       correctly). See "System clock epoch" section in systemd(1) for details.
       systemd will set the clock when initializing, but
       /var/lib/systemd/timesync/clock might not yet be available at that
       point.  systemd-timesyncd will advance the clock when it is started and
       notices that the system clock is before the modification time of
       /var/lib/systemd/timesync/clock.

FILES
       /var/lib/systemd/timesync/clock
	   The modification time ("mtime") of this file is updated on each
	   successful NTP synchronization or after each SaveIntervalSec= time
	   interval, as specified in timesyncd.conf(5).

	   If present, the modification time of this file is used for the
	   epoch by systemd(1) and systemd-timesyncd.service.

	   Added in version 219.

       /run/systemd/timesync/synchronized
	   A file that is touched on each successful synchronization to assist
	   systemd-time-wait-sync.service(8) service and other applications in
	   detecting synchronization to an accurate reference clock.

	   Added in version 239.

SEE ALSO
       systemd(1), timesyncd.conf(5), systemd.network(5), systemd-
       networkd.service(8), systemd-time-wait-sync.service(8),
       systemd.special(7), timedatectl(1), localtime(5), hwclock(8)

systemd 258					  SYSTEMD-TIMESYNCD.SERVICE(8)