systemd/man/org.freedesktop.timedate1.xml
Zbigniew Jędrzejewski-Szmek 4fb222c4b2 man: run dbus api docs through the updater
This replaces the api export tables with updated versions, and inserts
comments for all "undocumented" items. The slow work of documented them
is left for later ;)

lxml does some formatting changes that are not significant for lxml processing,
but generate spurious difference in the diff (namely: ulinks become one-line,
and double quotes are used instead of single quotes for element attribute
values). This should be a one-time thing: subsequent renegeration should be
idempotent with regards to this.
2020-04-16 19:46:40 +02:00

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XML

<?xml version='1.0'?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" >
<!-- SPDX-License-Identifier: LGPL-2.1+ -->
<refentry id="org.freedesktop.timedate1" conditional='ENABLE_TIMEDATED'
xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>org.freedesktop.timedate1</title>
<productname>systemd</productname>
</refentryinfo>
<refmeta>
<refentrytitle>org.freedesktop.timedate1</refentrytitle>
<manvolnum>5</manvolnum>
</refmeta>
<refnamediv>
<refname>org.freedesktop.timedate1</refname>
<refpurpose>The D-Bus interface of systemd-timedated</refpurpose>
</refnamediv>
<refsect1>
<title>Introduction</title>
<para>
<citerefentry><refentrytitle>systemd-timedated.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
is a system service that can be used to control the system time and related settings. This page
describes the D-Bus interface.</para>
</refsect1>
<refsect1>
<title>The D-Bus API</title>
<para>The service exposes the following interfaces on the bus:</para>
<programlisting>
$ gdbus introspect --system \
--dest org.freedesktop.timedate1 \
--object-path /org/freedesktop/timedate1
node /org/freedesktop/timedate1 {
interface org.freedesktop.timedate1 {
methods:
SetTime(in x usec_utc,
in b relative,
in b interactive);
SetTimezone(in s timezone,
in b interactive);
SetLocalRTC(in b local_rtc,
in b fix_system,
in b interactive);
SetNTP(in b use_ntp,
in b interactive);
ListTimezones(out as timezones);
properties:
readonly s Timezone = '...';
readonly b LocalRTC = ...;
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly b CanNTP = ...;
readonly b NTP = ...;
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly b NTPSynchronized = ...;
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly t TimeUSec = ...;
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly t RTCTimeUSec = ...;
};
interface org.freedesktop.DBus.Peer { ... };
interface org.freedesktop.DBus.Introspectable { ... };
interface org.freedesktop.DBus.Properties { ... };
};
</programlisting>
<!--method ListTimezones is not documented!-->
<!--property Timezone is not documented!-->
<!--property LocalRTC is not documented!-->
<!--property CanNTP is not documented!-->
<!--property NTP is not documented!-->
<!--property NTPSynchronized is not documented!-->
<!--property TimeUSec is not documented!-->
<!--property RTCTimeUSec is not documented!-->
<refsect2>
<title>Methods</title>
<para>Use <function>SetTime()</function> to change the system clock. Pass a value of microseconds since
the UNIX epoch (1 Jan 1970 UTC). If <varname>relative</varname> is true, the passed usec value will be
added to the current system time, if it is false the current system time will be set to the passed usec
value. If the system time is set with this call the RTC will be updated as well.</para>
<para>Use <function>SetTimezone()</function> to set the system timezone. Pass a value like
<literal>Europe/Berlin</literal> to set the timezone. Valid timezones are listed in
<filename>/usr/share/zoneinfo/zone.tab</filename>. If the RTC is configured to be maintained in local
time, it will be updated accordingly.</para>
<para>Use <function>SetLocalRTC()</function> to control whether the RTC is in local time or UTC. It is
strongly recommended to maintain the RTC in UTC. Some OSes (Windows) however maintain the RTC in local
time, which might make it necessary to enable this feature. However, this creates various problems as
daylight changes might be missed. If <varname>fix_system</varname> is passed <literal>true</literal>,
the time from the RTC is read again and the system clock adjusted according to the new setting. If
<varname>fix_system</varname> is passed <literal>false</literal> the system time is written to the RTC
taking the new setting into account. Use <varname>fix_system=true</varname> in installers and livecds
where the RTC is probably more reliable than the system time. Use <varname>fix_system=false</varname>
in configuration UIs that are run during normal operation and where the system clock is probably more
reliable than the RTC.</para>
<para>Use <function>SetNTP()</function> to control whether the system clock is synchronized with the
network using <filename>systemd-timesyncd</filename>. This will enable and start or disable and stop
the chosen time synchronization service.</para>
<para>Whenever the timezone and local_rtc settings are changed via the daemon
<function>PropertyChanged</function> signals are sent out to which clients can subscribe. Changing the
time settings using this interface is authenticated via PolicyKit.</para>
<para>Note that this service will not inform you about system time changes. Use
<citerefentry project="man-pages"><refentrytitle>timerfd</refentrytitle><manvolnum>3</manvolnum></citerefentry>
with <constant>CLOCK_REALTIME</constant> and <constant>TFD_TIMER_CANCEL_ON_SET</constant> for that.
</para>
<para>The <varname>user_interaction</varname> boolean parameters can be used to control whether
PolicyKit should interactively ask the user for authentication credentials if it needs to.</para>
<para>The PolicyKit action for <function>SetTimezone()</function> is
<interfacename>org.freedesktop.timedate1.set-timezone</interfacename>. For
<function>SetLocalRTC()</function> it is
<interfacename>org.freedesktop.timedate1.set-local-rtc</interfacename>, for
<function>SetTime()</function> it is <interfacename>org.freedesktop.timedate1.set-time</interfacename>
and for <function>SetNTP()</function> it is
<interfacename>org.freedesktop.timedate1.set-ntp</interfacename>.</para>
</refsect2>
</refsect1>
<refsect1>
<title>Versioning</title>
<para>These D-Bus interfaces follow <ulink url="http://0pointer.de/blog/projects/versioning-dbus.html">
the usual interface versioning guidelines</ulink>.</para>
</refsect1>
<refsect1>
<title>See also</title>
<para><ulink url="https://lists.freedesktop.org/archives/systemd-devel/2011-May/002526.html">More information on how the system clock and RTC interact</ulink></para>
</refsect1>
</refentry>