# systemd-timedated.service

systemd

systemd-timedated.service

8

systemd-timedated.service

systemd-timedated

Time and date bus mechanism

`systemd-timedated.service`

`/usr/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)` 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)` and `org.freedesktop.LogControl1(5)` for information about the D-Bus API.

# List of network time synchronization services

`systemd-timedated` 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 `/usr/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).

<div class="example">

<div class="title">

`ntp-units.d/` entry for `systemd-timesyncd`

</div>

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

</div>

If the environment variable `$SYSTEMD_TIMEDATED_NTP_SERVICES` is set, `systemd-timedated` 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.

<div class="example">

<div class="title">

An override that specifies that `chronyd` should be used if available

</div>

    SYSTEMD_TIMEDATED_NTP_SERVICES=chronyd.service:systemd-timesyncd.service

</div>

# See Also

`systemd(1)`, `timedatectl(1)`, `localtime(5)`, `hwclock(8)`, `systemd-timesyncd(8)`, `org.freedesktop.timedate1(5)`