1 <?xml version='1.0'?> <!--*-nxml-*-->
2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
6 This file is part of systemd.
8 Copyright 2012 Lennart Poettering
10 systemd is free software; you can redistribute it and/or modify it
11 under the terms of the GNU Lesser General Public License as published by
12 the Free Software Foundation; either version 2.1 of the License, or
13 (at your option) any later version.
15 systemd is distributed in the hope that it will be useful, but
16 WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 Lesser General Public License for more details.
20 You should have received a copy of the GNU Lesser General Public License
21 along with systemd; If not, see <http://www.gnu.org/licenses/>.
24 <refentry id="timedatectl" conditional='ENABLE_TIMEDATED'>
27 <title>timedatectl</title>
28 <productname>systemd</productname>
32 <contrib>Developer</contrib>
33 <firstname>Lennart</firstname>
34 <surname>Poettering</surname>
35 <email>lennart@poettering.net</email>
41 <refentrytitle>timedatectl</refentrytitle>
42 <manvolnum>1</manvolnum>
46 <refname>timedatectl</refname>
47 <refpurpose>Control the system time and date</refpurpose>
52 <command>timedatectl <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="req">COMMAND</arg></command>
57 <title>Description</title>
59 <para><command>timedatectl</command> may be used to
60 query and change the system clock and its
65 <title>Options</title>
67 <para>The following options are understood:</para>
71 <term><option>-h</option></term>
72 <term><option>--help</option></term>
74 <listitem><para>Prints a short help
75 text and exits.</para></listitem>
79 <term><option>--version</option></term>
81 <listitem><para>Prints a short version
82 string and exits.</para></listitem>
86 <term><option>--no-pager</option></term>
88 <listitem><para>Do not pipe output into a
89 pager.</para></listitem>
93 <term><option>--no-ask-password</option></term>
95 <listitem><para>Do not query the user
96 for authentication for privileged
97 operations.</para></listitem>
101 <term><option>-H</option></term>
102 <term><option>--host=</option></term>
104 <listitem><para>Execute operation
105 remotely. Specify a hostname, or
106 username and hostname separated by <literal>@</literal>,
107 to connect to. This will use SSH to
108 talk to the remote machine manager
109 instance.</para></listitem>
113 <term><option>-M</option></term>
114 <term><option>--machine=</option></term>
116 <listitem><para>Execute operation on a
117 local container. Specify a container
118 name to connect to.</para></listitem>
122 <term><option>--adjust-system-clock</option></term>
125 <command>set-local-rtc</command> is
126 invoked and this option is passed, the
127 system clock is synchronized from the
128 RTC again, taking the new setting into
129 account. Otherwise, the RTC is
130 synchronized from the system
131 clock.</para></listitem>
135 <para>The following commands are understood:</para>
139 <term><command>status</command></term>
141 <listitem><para>Show current settings
142 of the system clock and
143 RTC.</para></listitem>
147 <term><command>set-time [TIME]</command></term>
149 <listitem><para>Set the system clock
150 to the specified time. This will also
151 update the RTC time accordingly. The time
152 may be specified in the format
154 18:17:16".</para></listitem>
158 <term><command>set-timezone [TIMEZONE]</command></term>
160 <listitem><para>Set the system time
161 zone to the specified value. Available
162 timezones can be listed with
163 <command>list-timezones</command>. If
164 the RTC is configured to be in the
165 local time, this will also update the
166 RTC time. This call will alter the
167 <filename>/etc/localtime</filename>
169 <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>
171 information.</para></listitem>
175 <term><command>list-timezones</command></term>
177 <listitem><para>List available time
178 zones, one per line. Entries from the
179 list can be set as the system
181 <command>set-timezone</command>.</para></listitem>
185 <term><command>set-local-rtc [BOOL]</command></term>
187 <listitem><para>Takes a boolean
188 argument. If <literal>0</literal>, the
189 system is configured to maintain the
190 RTC in universal time. If
191 <literal>1</literal>, it will maintain
192 the RTC in local time instead. Note
193 that maintaining the RTC in the local
194 timezone is not fully supported and
195 will create various problems with time
196 zone changes and daylight saving
197 adjustments. If at all possible, keep the
198 RTC in UTC mode. Note that invoking this
199 will also synchronize the RTC from the
201 <option>--adjust-system-clock</option> is
202 passed (see above). This command will
203 change the 3rd line of
204 <filename>/etc/adjtime</filename>, as
206 <citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>
210 <term><command>set-ntp [BOOL]</command></term>
212 <listitem><para>Takes a boolean
213 argument. Controls whether NTP based
214 network time synchronization is
216 available).</para></listitem>
224 <title>Exit status</title>
226 <para>On success 0 is returned, a non-zero failure
227 code otherwise.</para>
231 <title>Environment</title>
233 <variablelist class='environment-variables'>
235 <term><varname>$SYSTEMD_PAGER</varname></term>
236 <listitem><para>Pager to use when
237 <option>--no-pager</option> is not given;
238 overrides <varname>$PAGER</varname>. Setting
239 this to an empty string or the value
240 <literal>cat</literal> is equivalent to passing
241 <option>--no-pager</option>.</para></listitem>
247 <title>Examples</title>
248 <para>Show current settings:
251 Local time: Fri, 2012-11-02 09:26:46 CET
252 Universal time: Fri, 2012-11-02 08:26:46 UTC
253 RTC time: Fri, 2012-11-02 08:26:45
254 Timezone: Europe/Warsaw
260 Last DST change: CEST → CET, DST became inactive
261 Sun, 2012-10-28 02:59:59 CEST
262 Sun, 2012-10-28 02:00:00 CET
263 Next DST change: CET → CEST, DST will become active
264 the clock will jump one hour forward
265 Sun, 2013-03-31 01:59:59 CET
266 Sun, 2013-03-31 03:00:00 CEST
270 <para>Enable an NTP daemon (chronyd):
272 $ timedatectl set-ntp true
273 ==== AUTHENTICATING FOR org.freedesktop.timedate1.set-ntp ===
274 Authentication is required to control whether network time synchronization shall be enabled.
275 Authenticating as: user
277 ==== AUTHENTICATION COMPLETE ===
281 $ systemctl status chronyd.service
282 chronyd.service - NTP client/server
283 Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled)
284 Active: active (running) since Fri, 2012-11-02 09:36:25 CET; 5s ago
291 <title>See Also</title>
293 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
294 <citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
295 <citerefentry><refentrytitle>date</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
296 <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
297 <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
298 <citerefentry><refentrytitle>systemd-timedated.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>