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.
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16 WITHOUT ANY WARRANTY; without even the implied warranty of
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18 Lesser General Public License for more details.
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24 <refentry id="timedatectl">
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>--help</option></term>
72 <term><option>-h</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>Don't 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 the operation
105 remotely. Specify a hostname, or
106 username and hostname separated by @,
107 to connect to. This will use SSH to
109 system.</para></listitem>
113 <term><option>--adjust-system-clock</option></term>
116 <command>set-local-rtc</command> is
117 invoked and this option is passed the
118 system clock is synchronized from the
119 RTC again, taking the new setting into
120 account. Otherwise the RTC is
121 synchronized from the system
122 clock.</para></listitem>
126 <para>The following commands are understood:</para>
130 <term><command>status</command></term>
132 <listitem><para>Show current settings
133 of the system clock and
134 RTC.</para></listitem>
138 <term><command>set-time [TIME]</command></term>
140 <listitem><para>Set the system clock
141 to the specified time. This will also
142 update the RTC time accordingly. The time
143 may be specified in the format
145 18:17:16".</para></listitem>
149 <term><command>set-timezone [TIMEZONE]</command></term>
151 <listitem><para>Set the system time
152 zone to the specified value. Available
153 time zones can be listed with
154 <command>list-timezones</command>. If
155 the RTC is configured to be in the
156 local time this will also update the
157 RTC time. This call will alter the
158 <filename>/etc/localtime</filename>
160 <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>
162 information.</para></listitem>
166 <term><command>list-timezones</command></term>
168 <listitem><para>List available time
169 zones, one per line. Entries from the
170 list can be set as the system
172 <command>set-timezone</command>.</para></listitem>
176 <term><command>set-local-rtc [BOOL]</command></term>
178 <listitem><para>Takes a boolean
179 argument. If <literal>0</literal> the
180 system is configured to maintain the
181 RTC in universal time, if
182 <literal>1</literal> it will maintain
183 the RTC in local time instead. Note
184 that maintaining the RTC in the local
185 time zone is not fully supported and
186 will create various problems with time
187 zone changes and daylight saving
188 adjustments. If at all possible use
189 RTC in UTC. Note that invoking this
190 will also synchronize the RTC from the
192 <option>--adjust-system-clock</option> is
193 passed (see above). This command will
194 change the 3rd line of
195 <filename>/etc/adjtime</filename>, as
197 <citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>
201 <term><command>set-ntp [BOOL]</command></term>
203 <listitem><para>Takes a boolean
204 argument. Controls whether NTP based
205 network time synchronization is
207 available).</para></listitem>
215 <title>Exit status</title>
217 <para>On success 0 is returned, a non-zero failure
218 code otherwise.</para>
222 <title>Environment</title>
226 <term><varname>$SYSTEMD_PAGER</varname></term>
227 <listitem><para>Pager to use when
228 <option>--no-pager</option> is not given;
229 overrides <varname>$PAGER</varname>. Setting
230 this to an empty string or the value
231 <literal>cat</literal> is equivalent to passing
232 <option>--no-pager</option>.</para></listitem>
238 <title>Examples</title>
239 <para>Show current settings:
242 Local time: Fri, 2012-11-02 09:26:46 CET
243 Universal time: Fri, 2012-11-02 08:26:46 UTC
244 RTC time: Fri, 2012-11-02 08:26:45
245 Timezone: Europe/Warsaw
251 Last DST change: CEST → CET, DST became inactive
252 Sun, 2012-10-28 02:59:59 CEST
253 Sun, 2012-10-28 02:00:00 CET
254 Next DST change: CET → CEST, DST will become active
255 the clock will jump one hour forward
256 Sun, 2013-03-31 01:59:59 CET
257 Sun, 2013-03-31 03:00:00 CEST
261 <para>Enable an NTP daemon (chronyd):
263 $ timedatectl set-ntp true
264 ==== AUTHENTICATING FOR org.freedesktop.timedate1.set-ntp ===
265 Authentication is required to control whether network time synchronization shall be enabled.
266 Authenticating as: user
268 ==== AUTHENTICATION COMPLETE ===
272 $ systemctl status chronyd.service
273 chronyd.service - NTP client/server
274 Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled)
275 Active: active (running) since Fri, 2012-11-02 09:36:25 CET; 5s ago
282 <title>See Also</title>
284 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
285 <citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
286 <citerefentry><refentrytitle>date</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
287 <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
288 <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
289 <citerefentry><refentrytitle>systemd-timedated.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>