<?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" conditional='ENABLE_TIMEDATED' xmlns:xi="http://www.w3.org/2001/XInclude"> <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> <para>Use <citerefentry><refentrytitle>systemd-firstboot</refentrytitle><manvolnum>1</manvolnum></citerefentry> to initialize the system time zone for mounted (but not booted) system images.</para> </refsect1> <refsect1> <title>Options</title> <para>The following options are understood:</para> <variablelist> <varlistentry> <term><option>--no-ask-password</option></term> <listitem><para>Do not query the user for authentication for privileged operations.</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> <xi:include href="user-system-options.xml" xpointer="host" /> <xi:include href="user-system-options.xml" xpointer="machine" /> <xi:include href="standard-options.xml" xpointer="help" /> <xi:include href="standard-options.xml" xpointer="version" /> <xi:include href="standard-options.xml" xpointer="no-pager" /> </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, including whether network time synchronization is on. Note that whether network time synchronization is on simply reflects whether the <filename>systemd-timesyncd.service</filename> unit is enabled. Even if this command shows the status as off, a different service might still synchronize the clock with the network.</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 timezones 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 timezone 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 timezone is not fully supported and will create various problems with time zone changes and daylight saving adjustments. If at all possible, keep the RTC in UTC mode. 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 project='man-pages'><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 network time synchronization is active and enabled (if available). This enables and starts, or disables and stops the <filename>systemd-timesyncd.service</filename> unit. It does not affect the state of any other, unrelated network time synchronization services that might be installed on the system. This command is hence mostly equivalent to: <command>systemctl enable --now systemd-timesyncd.service</command> and <command>systemctl disable --now systemd-timesyncd.service</command>, but is protected by a different access policy.</para> <para>Note that even if time synchronization is turned off with this command, another unrelated system service might still synchronize the clock with the network. Also note that, strictly speaking, <filename>systemd-timesyncd.service</filename> does more than just network time synchronization, as it ensures a monotonic clock on systems without RTC even if no network is available. See <citerefentry><refentrytitle>systemd-timesyncd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> for details about this.</para></listitem> </varlistentry> </variablelist> </refsect1> <refsect1> <title>Exit status</title> <para>On success, 0 is returned, a non-zero failure code otherwise.</para> </refsect1> <xi:include href="less-variables.xml" /> <refsect1> <title>Examples</title> <para>Show current settings: <programlisting>$ timedatectl Local time: Di 2015-04-07 16:26:56 CEST Universal time: Di 2015-04-07 14:26:56 UTC RTC time: Di 2015-04-07 14:26:56 Time zone: Europe/Berlin (CEST, +0200) Network time on: yes NTP synchronized: yes RTC in local TZ: no</programlisting> </para> <para>Enable network time synchronization: <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 systemd-timesyncd.service ● systemd-timesyncd.service - Network Time Synchronization Loaded: loaded (/usr/lib/systemd/system/systemd-timesyncd.service; enabled) Active: active (running) since Mo 2015-03-30 14:20:38 CEST; 5s ago Docs: man:systemd-timesyncd.service(8) Main PID: 595 (systemd-timesyn) Status: "Using Time Server 216.239.38.15:123 (time4.google.com)." CGroup: /system.slice/systemd-timesyncd.service └─595 /usr/lib/systemd/systemd-timesyncd ...</programlisting> </para> </refsect1> <refsect1> <title>See Also</title> <para> <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry project='man-pages'><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry project='man-pages'><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>, <citerefentry><refentrytitle>systemd-timesyncd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-firstboot</refentrytitle><manvolnum>1</manvolnum></citerefentry> </para> </refsect1> </refentry>