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<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
This file is part of systemd.
Copyright 2012 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
-->
<refentry id="timedatectl">
<refentryinfo>
<title>timedatectl</title>
<productname>systemd</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>Lennart</firstname>
<surname>Poettering</surname>
<email>lennart@poettering.net</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta>
<refentrytitle>timedatectl</refentrytitle>
<manvolnum>1</manvolnum>
</refmeta>
<refnamediv>
<refname>timedatectl</refname>
<refpurpose>Control the system time and date</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>timedatectl <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="req">COMMAND</arg></command>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><command>timedatectl</command> may be used to
query and change the system clock and its
settings.</para>
</refsect1>
<refsect1>
<title>Options</title>
<para>The following options are understood:</para>
<variablelist>
<varlistentry>
<term><option>--help</option></term>
<term><option>-h</option></term>
<listitem><para>Prints a short help
text and exits.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--version</option></term>
<listitem><para>Prints a short version
string and exits.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--no-pager</option></term>
<listitem><para>Do not pipe output into a
pager.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--no-ask-password</option></term>
<listitem><para>Don't query the user
for authentication for privileged
operations.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-H</option></term>
<term><option>--host</option></term>
<listitem><para>Execute the operation
remotely. Specify a hostname, or
username and hostname separated by @,
to connect to. This will use SSH to
talk to a remote
system.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--adjust-system-clock</option></term>
<listitem><para>If
<command>set-local-rtc</command> is
invoked and this option is passed the
system clock is synchronized from the
RTC again, taking the new setting into
account. Otherwise the RTC is
synchronized from the system
clock.</para></listitem>
</varlistentry>
</variablelist>
<para>The following commands are understood:</para>
<variablelist>
<varlistentry>
<term><command>status</command></term>
<listitem><para>Show current settings
of the system clock and
RTC.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>set-time [TIME]</command></term>
<listitem><para>Set the system clock
to the specified time. This will also
update the RTC time accordingly. The time
may be specified in the format
"2012-10-30
18:17:16".</para></listitem>
</varlistentry>
<varlistentry>
<term><command>set-timezone [TIMEZONE]</command></term>
<listitem><para>Set the system time
zone to the specified value. Available
time zones can be listed with
<command>list-timezones</command>. If
the RTC is configured to be in the
local time this will also update the
RTC time. This call will alter the
<filename>/etc/localtime</filename>
symlink. See
<citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>
for more
information.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>list-timezones</command></term>
<listitem><para>List available time
zones, one per line. Entries from the
list can be set as the system
time zone with
<command>set-timezone</command>.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>set-local-rtc [BOOL]</command></term>
<listitem><para>Takes a boolean
argument. If <literal>0</literal> the
system is configured to maintain the
RTC in universal time, if
<literal>1</literal> it will maintain
the RTC in local time instead. Note
that maintaining the RTC in the local
time zone is not fully supported and
will create various problems with time
zone changes and daylight saving
adjustments. If at all possible use
RTC in UTC. Note that invoking this
will also synchronize the RTC from the
system clock, unless
<option>--adjust-system-clock</option> is
passed (see above). This command will
change the 3rd line of
<filename>/etc/adjtime</filename>, as
documented in
<citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>set-ntp [BOOL]</command></term>
<listitem><para>Takes a boolean
argument. Controls whether NTP based
network time synchronization is
enabled (if
available).</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Exit status</title>
<para>On success 0 is returned, a non-zero failure
code otherwise.</para>
</refsect1>
<refsect1>
<title>Environment</title>
<variablelist class='environment-variables'>
<varlistentry>
<term><varname>$SYSTEMD_PAGER</varname></term>
<listitem><para>Pager to use when
<option>--no-pager</option> is not given;
overrides <varname>$PAGER</varname>. Setting
this to an empty string or the value
<literal>cat</literal> is equivalent to passing
<option>--no-pager</option>.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Examples</title>
<para>Show current settings:
<programlisting>
$ timedatectl
Local time: Fri, 2012-11-02 09:26:46 CET
Universal time: Fri, 2012-11-02 08:26:46 UTC
RTC time: Fri, 2012-11-02 08:26:45
Timezone: Europe/Warsaw
UTC offset: +0100
NTP enabled: no
NTP synchronized: no
RTC in local TZ: no
DST active: no
Last DST change: CEST → CET, DST became inactive
Sun, 2012-10-28 02:59:59 CEST
Sun, 2012-10-28 02:00:00 CET
Next DST change: CET → CEST, DST will become active
the clock will jump one hour forward
Sun, 2013-03-31 01:59:59 CET
Sun, 2013-03-31 03:00:00 CEST
</programlisting>
</para>
<para>Enable an NTP daemon (chronyd):
<programlisting>
$ timedatectl set-ntp true
==== AUTHENTICATING FOR org.freedesktop.timedate1.set-ntp ===
Authentication is required to control whether network time synchronization shall be enabled.
Authenticating as: user
Password: ********
==== AUTHENTICATION COMPLETE ===
</programlisting>
<programlisting>
$ systemctl status chronyd.service
chronyd.service - NTP client/server
Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled)
Active: active (running) since Fri, 2012-11-02 09:36:25 CET; 5s ago
...
</programlisting>
</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>date</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-timedated.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>
|
