chiark / gitweb /
udevadm-settle: add missing brace
[elogind.git] / man / timedatectl.xml
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">
4
5 <!--
6   This file is part of systemd.
7
8   Copyright 2012 Lennart Poettering
9
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.
14
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.
19
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/>.
22 -->
23
24 <refentry id="timedatectl" conditional='ENABLE_TIMEDATED'>
25
26         <refentryinfo>
27                 <title>timedatectl</title>
28                 <productname>systemd</productname>
29
30                 <authorgroup>
31                         <author>
32                                 <contrib>Developer</contrib>
33                                 <firstname>Lennart</firstname>
34                                 <surname>Poettering</surname>
35                                 <email>lennart@poettering.net</email>
36                         </author>
37                 </authorgroup>
38         </refentryinfo>
39
40         <refmeta>
41                 <refentrytitle>timedatectl</refentrytitle>
42                 <manvolnum>1</manvolnum>
43         </refmeta>
44
45         <refnamediv>
46                 <refname>timedatectl</refname>
47                 <refpurpose>Control the system time and date</refpurpose>
48         </refnamediv>
49
50         <refsynopsisdiv>
51                 <cmdsynopsis>
52                         <command>timedatectl <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="req">COMMAND</arg></command>
53                 </cmdsynopsis>
54         </refsynopsisdiv>
55
56         <refsect1>
57                 <title>Description</title>
58
59                 <para><command>timedatectl</command> may be used to
60                 query and change the system clock and its
61                 settings.</para>
62         </refsect1>
63
64         <refsect1>
65                 <title>Options</title>
66
67                 <para>The following options are understood:</para>
68
69                 <variablelist>
70                         <varlistentry>
71                                 <term><option>-h</option></term>
72                                 <term><option>--help</option></term>
73
74                                 <listitem><para>Prints a short help
75                                 text and exits.</para></listitem>
76                         </varlistentry>
77
78                         <varlistentry>
79                                 <term><option>--version</option></term>
80
81                                 <listitem><para>Prints a short version
82                                 string and exits.</para></listitem>
83                         </varlistentry>
84
85                         <varlistentry>
86                                 <term><option>--no-pager</option></term>
87
88                                 <listitem><para>Do not pipe output into a
89                                 pager.</para></listitem>
90                         </varlistentry>
91
92                         <varlistentry>
93                                 <term><option>--no-ask-password</option></term>
94
95                                 <listitem><para>Do not query the user
96                                 for authentication for privileged
97                                 operations.</para></listitem>
98                         </varlistentry>
99
100                         <varlistentry>
101                                 <term><option>-H</option></term>
102                                 <term><option>--host=</option></term>
103
104                                 <listitem><para>Execute the 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>
110                         </varlistentry>
111
112                         <varlistentry>
113                                 <term><option>-M</option></term>
114                                 <term><option>--machine=</option></term>
115
116                                 <listitem><para>Execute operation on a
117                                 local container. Specify a container
118                                 name to connect to.</para></listitem>
119                         </varlistentry>
120
121                         <varlistentry>
122                                 <term><option>--adjust-system-clock</option></term>
123
124                                 <listitem><para>If
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>
132                         </varlistentry>
133                 </variablelist>
134
135                 <para>The following commands are understood:</para>
136
137                 <variablelist>
138                         <varlistentry>
139                                 <term><command>status</command></term>
140
141                                 <listitem><para>Show current settings
142                                 of the system clock and
143                                 RTC.</para></listitem>
144                         </varlistentry>
145
146                         <varlistentry>
147                                 <term><command>set-time [TIME]</command></term>
148
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
153                                 "2012-10-30
154                                 18:17:16".</para></listitem>
155                         </varlistentry>
156
157                         <varlistentry>
158                                 <term><command>set-timezone [TIMEZONE]</command></term>
159
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>
168                                 symlink. See
169                                 <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>
170                                 for more
171                                 information.</para></listitem>
172                         </varlistentry>
173
174                         <varlistentry>
175                                 <term><command>list-timezones</command></term>
176
177                                 <listitem><para>List available time
178                                 zones, one per line. Entries from the
179                                 list can be set as the system
180                                 timezone with
181                                 <command>set-timezone</command>.</para></listitem>
182                         </varlistentry>
183
184                         <varlistentry>
185                                 <term><command>set-local-rtc [BOOL]</command></term>
186
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
200                                 system clock, unless
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
205                                 documented in
206                                 <citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>
207                         </varlistentry>
208
209                         <varlistentry>
210                                 <term><command>set-ntp [BOOL]</command></term>
211
212                                 <listitem><para>Takes a boolean
213                                 argument. Controls whether NTP based
214                                 network time synchronization is
215                                 enabled (if
216                                 available).</para></listitem>
217                         </varlistentry>
218
219                 </variablelist>
220
221         </refsect1>
222
223         <refsect1>
224                 <title>Exit status</title>
225
226                 <para>On success 0 is returned, a non-zero failure
227                 code otherwise.</para>
228         </refsect1>
229
230         <refsect1>
231                 <title>Environment</title>
232
233                 <variablelist class='environment-variables'>
234                         <varlistentry>
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>
242                         </varlistentry>
243                 </variablelist>
244         </refsect1>
245
246         <refsect1>
247                 <title>Examples</title>
248                 <para>Show current settings:
249                 <programlisting>
250 $ timedatectl
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
255       UTC offset: +0100
256      NTP enabled: no
257 NTP synchronized: no
258  RTC in local TZ: no
259       DST active: no
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
267                 </programlisting>
268                 </para>
269
270                 <para>Enable an NTP daemon (chronyd):
271                 <programlisting>
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
276 Password: ********
277 ==== AUTHENTICATION COMPLETE ===
278                 </programlisting>
279
280                 <programlisting>
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
285 ...
286                 </programlisting>
287                 </para>
288         </refsect1>
289
290         <refsect1>
291                 <title>See Also</title>
292                 <para>
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>
299                 </para>
300         </refsect1>
301
302 </refentry>