1 <?xml version='
1.0'
?> <!--*-nxml-*-->
2 <!DOCTYPE refentry PUBLIC
"-//OASIS//DTD DocBook XML V4.5//EN"
3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
4 <!-- SPDX-License-Identifier: LGPL-2.1+ -->
6 <refentry id=
"systemd-timedated.service" conditional='ENABLE_TIMEDATED'
>
9 <title>systemd-timedated.service
</title>
10 <productname>systemd
</productname>
14 <refentrytitle>systemd-timedated.service
</refentrytitle>
15 <manvolnum>8</manvolnum>
19 <refname>systemd-timedated.service
</refname>
20 <refname>systemd-timedated
</refname>
21 <refpurpose>Time and date bus mechanism
</refpurpose>
25 <para><filename>systemd-timedated.service
</filename></para>
26 <para><filename>/usr/lib/systemd/systemd-timedated
</filename></para>
30 <title>Description
</title>
32 <para><filename>systemd-timedated.service
</filename> is a system service
33 that may be used as a mechanism to change the system clock and
34 timezone, as well as to enable/disable network time synchronization.
35 <filename>systemd-timedated
</filename> is automatically activated
36 on request and terminates itself when it is unused.
</para>
39 <citerefentry><refentrytitle>timedatectl
</refentrytitle><manvolnum>1</manvolnum></citerefentry>
40 is a command line client to this service.
</para>
42 <para><filename>systemd-timedated
</filename> currently offers access to
43 the following four settings:
45 <listitem><para>The system time
</para></listitem>
47 <listitem><para>The system timezone
</para></listitem>
49 <listitem><para>A boolean controlling whether the system RTC is in local or UTC
50 timezone
</para></listitem>
52 <listitem><para>Whether the time synchronization service is enabled/started or
53 disabled/stopped, see next section.
</para></listitem>
54 </itemizedlist></para>
57 <citerefentry><refentrytitle>org.freedesktop.timedate1
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
59 <citerefentry><refentrytitle>org.freedesktop.LogControl1
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
60 for information about the D-Bus API.
</para>
64 <title>List of network time synchronization services
</title>
66 <para><command>systemd-timesyncd
</command> will look for files with a
<literal>.list
</literal> extension
67 in
<filename>ntp-units.d/
</filename> directories. Each file is parsed as a list of unit names, one per
68 line. Empty lines and lines with comments (
<literal>#
</literal>) are ignored. Files are read from
69 <filename>/usr/lib/systemd/ntp-units.d/
</filename> and the corresponding directories under
70 <filename>/etc/
</filename>,
<filename>/run/
</filename>,
<filename>/usr/local/lib/
</filename>. Files in
71 <filename>/etc/
</filename> override files with the same name in
<filename>/run/
</filename>,
72 <filename>/usr/local/lib/
</filename>, and
<filename>/usr/lib/
</filename>. Files in
73 <filename>/run/
</filename> override files with the same name under
<filename>/usr/
</filename>. Packages
74 should install their configuration files in
<filename>/usr/lib/
</filename> (distribution packages) or
75 <filename>/usr/local/lib/
</filename> (local installs).
</para>
78 <title><filename>ntp-units.d/
</filename> entry for
<command>systemd-timesyncd
</command></title>
79 <programlisting># /usr/lib/systemd/ntp-units.d/
80-systemd-timesync.list
80 systemd-timesyncd.service
84 <para>If the environment variable
<varname>$SYSTEMD_TIMEDATED_NTP_SERVICES
</varname> is set,
85 <command>systemd-timesyncd
</command> will parse the contents of that variable as a colon-separated list
86 of unit names. When set, this variable overrides the file-based list described above.
</para>
89 <title>An override that specifies that
<command>chronyd
</command> should be used if available
</title>
90 <programlisting>SYSTEMD_TIMEDATED_NTP_SERVICES=chronyd.service:systemd-timesyncd.service
</programlisting>
95 <title>See Also
</title>
97 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
98 <citerefentry><refentrytitle>timedatectl
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
99 <citerefentry><refentrytitle>localtime
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
100 <citerefentry project='man-pages'
><refentrytitle>hwclock
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
101 <citerefentry><refentrytitle>systemd-timesyncd
</refentrytitle><manvolnum>8</manvolnum></citerefentry>