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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">
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>--help</option></term>
72                                 <term><option>-h</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>Don't 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 @,
107                                 to connect to. This will use SSH to
108                                 talk to a remote
109                                 system.</para></listitem>
110                         </varlistentry>
111
112                         <varlistentry>
113                                 <term><option>--adjust-system-clock</option></term>
114
115                                 <listitem><para>If
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>
123                         </varlistentry>
124                 </variablelist>
125
126                 <para>The following commands are understood:</para>
127
128                 <variablelist>
129                         <varlistentry>
130                                 <term><command>status</command></term>
131
132                                 <listitem><para>Show current settings
133                                 of the system clock and
134                                 RTC.</para></listitem>
135                         </varlistentry>
136
137                         <varlistentry>
138                                 <term><command>set-time [TIME]</command></term>
139
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
144                                 "2012-10-30
145                                 18:17:16".</para></listitem>
146                         </varlistentry>
147
148                         <varlistentry>
149                                 <term><command>set-timezone [TIMEZONE]</command></term>
150
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>
159                                 symlink. See
160                                 <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>
161                                 for more
162                                 information.</para></listitem>
163                         </varlistentry>
164
165                         <varlistentry>
166                                 <term><command>list-timezones</command></term>
167
168                                 <listitem><para>List available time
169                                 zones, one per line. Entries from the
170                                 list can be set as the system
171                                 time zone with
172                                 <command>set-timezone</command>.</para></listitem>
173                         </varlistentry>
174
175                         <varlistentry>
176                                 <term><command>set-local-rtc [BOOL]</command></term>
177
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
191                                 system clock, unless
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
196                                 documented in
197                                 <citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>
198                         </varlistentry>
199
200                         <varlistentry>
201                                 <term><command>set-ntp [BOOL]</command></term>
202
203                                 <listitem><para>Takes a boolean
204                                 argument. Controls whether NTP based
205                                 network time synchronization is
206                                 enabled (if
207                                 available).</para></listitem>
208                         </varlistentry>
209
210                 </variablelist>
211
212         </refsect1>
213
214         <refsect1>
215                 <title>Exit status</title>
216
217                 <para>On success 0 is returned, a non-zero failure
218                 code otherwise.</para>
219         </refsect1>
220
221         <refsect1>
222                 <title>Environment</title>
223
224                 <variablelist>
225                         <varlistentry>
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>
233                         </varlistentry>
234                 </variablelist>
235         </refsect1>
236
237         <refsect1>
238                 <title>Examples</title>
239                 <para>Show current settings:
240                 <programlisting>
241 $ timedatectl
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
246       UTC offset: +0100
247      NTP enabled: no
248 NTP synchronized: no
249  RTC in local TZ: no
250       DST active: no
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
258                 </programlisting>
259                 </para>
260
261                 <para>Enable an NTP daemon (chronyd):
262                 <programlisting>
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
267 Password: ********
268 ==== AUTHENTICATION COMPLETE ===
269                 </programlisting>
270
271                 <programlisting>
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
276 ...
277                 </programlisting>
278                 </para>
279         </refsect1>
280
281         <refsect1>
282                 <title>See Also</title>
283                 <para>
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>
290                 </para>
291         </refsect1>
292
293 </refentry>