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man: drop references to "cgroup" wher appropriate
[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
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8   Copyright 2012 Lennart Poettering
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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>-P</option></term>
102                                 <term><option>--privileged</option></term>
103
104                                 <listitem><para>Acquire privileges via PolicyKit
105                                 before executing the operation.</para></listitem>
106                         </varlistentry>
107
108                         <varlistentry>
109                                 <term><option>-H</option></term>
110                                 <term><option>--host</option></term>
111
112                                 <listitem><para>Execute the operation
113                                 remotely. Specify a hostname, or
114                                 username and hostname separated by <literal>@</literal>,
115                                 to connect to. This will use SSH to
116                                 talk to a remote
117                                 system.</para></listitem>
118                         </varlistentry>
119
120                         <varlistentry>
121                                 <term><option>--adjust-system-clock</option></term>
122
123                                 <listitem><para>If
124                                 <command>set-local-rtc</command> is
125                                 invoked and this option is passed, the
126                                 system clock is synchronized from the
127                                 RTC again, taking the new setting into
128                                 account. Otherwise, the RTC is
129                                 synchronized from the system
130                                 clock.</para></listitem>
131                         </varlistentry>
132                 </variablelist>
133
134                 <para>The following commands are understood:</para>
135
136                 <variablelist>
137                         <varlistentry>
138                                 <term><command>status</command></term>
139
140                                 <listitem><para>Show current settings
141                                 of the system clock and
142                                 RTC.</para></listitem>
143                         </varlistentry>
144
145                         <varlistentry>
146                                 <term><command>set-time [TIME]</command></term>
147
148                                 <listitem><para>Set the system clock
149                                 to the specified time. This will also
150                                 update the RTC time accordingly. The time
151                                 may be specified in the format
152                                 "2012-10-30
153                                 18:17:16".</para></listitem>
154                         </varlistentry>
155
156                         <varlistentry>
157                                 <term><command>set-timezone [TIMEZONE]</command></term>
158
159                                 <listitem><para>Set the system time
160                                 zone to the specified value. Available
161                                 timezones can be listed with
162                                 <command>list-timezones</command>. If
163                                 the RTC is configured to be in the
164                                 local time, this will also update the
165                                 RTC time. This call will alter the
166                                 <filename>/etc/localtime</filename>
167                                 symlink. See
168                                 <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>
169                                 for more
170                                 information.</para></listitem>
171                         </varlistentry>
172
173                         <varlistentry>
174                                 <term><command>list-timezones</command></term>
175
176                                 <listitem><para>List available time
177                                 zones, one per line. Entries from the
178                                 list can be set as the system
179                                 timezone with
180                                 <command>set-timezone</command>.</para></listitem>
181                         </varlistentry>
182
183                         <varlistentry>
184                                 <term><command>set-local-rtc [BOOL]</command></term>
185
186                                 <listitem><para>Takes a boolean
187                                 argument. If <literal>0</literal>, the
188                                 system is configured to maintain the
189                                 RTC in universal time. If
190                                 <literal>1</literal>, it will maintain
191                                 the RTC in local time instead. Note
192                                 that maintaining the RTC in the local
193                                 timezone is not fully supported and
194                                 will create various problems with time
195                                 zone changes and daylight saving
196                                 adjustments. If at all possible, keep the
197                                 RTC in UTC mode. Note that invoking this
198                                 will also synchronize the RTC from the
199                                 system clock, unless
200                                 <option>--adjust-system-clock</option> is
201                                 passed (see above). This command will
202                                 change the 3rd line of
203                                 <filename>/etc/adjtime</filename>, as
204                                 documented in
205                                 <citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>
206                         </varlistentry>
207
208                         <varlistentry>
209                                 <term><command>set-ntp [BOOL]</command></term>
210
211                                 <listitem><para>Takes a boolean
212                                 argument. Controls whether NTP based
213                                 network time synchronization is
214                                 enabled (if
215                                 available).</para></listitem>
216                         </varlistentry>
217
218                 </variablelist>
219
220         </refsect1>
221
222         <refsect1>
223                 <title>Exit status</title>
224
225                 <para>On success 0 is returned, a non-zero failure
226                 code otherwise.</para>
227         </refsect1>
228
229         <refsect1>
230                 <title>Environment</title>
231
232                 <variablelist class='environment-variables'>
233                         <varlistentry>
234                                 <term><varname>$SYSTEMD_PAGER</varname></term>
235                                 <listitem><para>Pager to use when
236                                 <option>--no-pager</option> is not given;
237                                 overrides <varname>$PAGER</varname>.  Setting
238                                 this to an empty string or the value
239                                 <literal>cat</literal> is equivalent to passing
240                                 <option>--no-pager</option>.</para></listitem>
241                         </varlistentry>
242                 </variablelist>
243         </refsect1>
244
245         <refsect1>
246                 <title>Examples</title>
247                 <para>Show current settings:
248                 <programlisting>
249 $ timedatectl
250       Local time: Fri, 2012-11-02 09:26:46 CET
251   Universal time: Fri, 2012-11-02 08:26:46 UTC
252         RTC time: Fri, 2012-11-02 08:26:45
253         Timezone: Europe/Warsaw
254       UTC offset: +0100
255      NTP enabled: no
256 NTP synchronized: no
257  RTC in local TZ: no
258       DST active: no
259  Last DST change: CEST → CET, DST became inactive
260                   Sun, 2012-10-28 02:59:59 CEST
261                   Sun, 2012-10-28 02:00:00 CET
262  Next DST change: CET → CEST, DST will become active
263                   the clock will jump one hour forward
264                   Sun, 2013-03-31 01:59:59 CET
265                   Sun, 2013-03-31 03:00:00 CEST
266                 </programlisting>
267                 </para>
268
269                 <para>Enable an NTP daemon (chronyd):
270                 <programlisting>
271 $ timedatectl set-ntp true
272 ==== AUTHENTICATING FOR org.freedesktop.timedate1.set-ntp ===
273 Authentication is required to control whether network time synchronization shall be enabled.
274 Authenticating as: user
275 Password: ********
276 ==== AUTHENTICATION COMPLETE ===
277                 </programlisting>
278
279                 <programlisting>
280 $ systemctl status chronyd.service
281 chronyd.service - NTP client/server
282           Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled)
283           Active: active (running) since Fri, 2012-11-02 09:36:25 CET; 5s ago
284 ...
285                 </programlisting>
286                 </para>
287         </refsect1>
288
289         <refsect1>
290                 <title>See Also</title>
291                 <para>
292                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
293                         <citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
294                         <citerefentry><refentrytitle>date</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
295                         <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
296                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
297                         <citerefentry><refentrytitle>systemd-timedated.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
298                 </para>
299         </refsect1>
300
301 </refentry>