# phpman > man > systemd-timedated.service(8)

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## NAME
       systemd-timedated.service, systemd-timedated - Time and date bus mechanism

## SYNOPSIS
       systemd-timedated.service

       /lib/systemd/systemd-timedated

## DESCRIPTION
       systemd-timedated.service is a system service that may be used as a mechanism to change the
       system clock and timezone, as well as to enable/disable network time synchronization.
       systemd-timedated is automatically activated on request and terminates itself when it is
       unused.

       The tool [**timedatectl**(1)](https://www.chedong.com/phpMan.php/man/timedatectl/1/markdown) is a command line client to this service.

       systemd-timedated currently offers access to the following four settings:

       •   The system time

       •   The system timezone

       •   A boolean controlling whether the system RTC is in local or UTC timezone

       •   Whether the time synchronization service is enabled/started or disabled/stopped, see next
           section.

       See [**org.freedesktop.timedate1**(5)](https://www.chedong.com/phpMan.php/man/org.freedesktop.timedate1/5/markdown) and [**org.freedesktop.LogControl1**(5)](https://www.chedong.com/phpMan.php/man/org.freedesktop.LogControl1/5/markdown) for information about the
       D-Bus API.

## LIST OF NETWORK TIME SYNCHRONIZATION SERVICES
       **systemd-timesyncd** will look for files with a ".list" extension in ntp-units.d/ directories.
       Each file is parsed as a list of unit names, one per line. Empty lines and lines with
       comments ("#") are ignored. Files are read from /usr/lib/systemd/ntp-units.d/ and the
       corresponding directories under /etc/, /run/, /usr/local/lib/. Files in /etc/ override files
       with the same name in /run/, /usr/local/lib/, and /lib/. Files in /run/ override files with
       the same name under /usr/. Packages should install their configuration files in /usr/lib/
       (distribution packages) or /usr/local/lib/ (local installs).

### Example 1. ntp-units.d/ entry for systemd-timesyncd

           # /usr/lib/systemd/ntp-units.d/80-systemd-timesync.list
           systemd-timesyncd.service

       If the environment variable _$SYSTEMD_TIMEDATED_NTP_SERVICES_ is set, **systemd-timesyncd** will
       parse the contents of that variable as a colon-separated list of unit names. When set, this
       variable overrides the file-based list described above.

### Example 2. An override that specifies that chronyd should be used if available

           SYSTEMD_TIMEDATED_NTP_SERVICES=chronyd.service:systemd-timesyncd.service

## SEE ALSO
       [**systemd**(1)](https://www.chedong.com/phpMan.php/man/systemd/1/markdown), [**timedatectl**(1)](https://www.chedong.com/phpMan.php/man/timedatectl/1/markdown), [**localtime**(5)](https://www.chedong.com/phpMan.php/man/localtime/5/markdown), [**hwclock**(8)](https://www.chedong.com/phpMan.php/man/hwclock/8/markdown), [**systemd-timesyncd**(8)](https://www.chedong.com/phpMan.php/man/systemd-timesyncd/8/markdown)



systemd 249                                                             [SYSTEMD-TIMEDATED.SERVICE(8)](https://www.chedong.com/phpMan.php/man/SYSTEMD-TIMEDATED.SERVICE/8/markdown)