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'
25 xmlns:
xi=
"http://www.w3.org/2001/XInclude">
28 <title>timedatectl
</title>
29 <productname>systemd
</productname>
33 <contrib>Developer
</contrib>
34 <firstname>Lennart
</firstname>
35 <surname>Poettering
</surname>
36 <email>lennart@poettering.net
</email>
42 <refentrytitle>timedatectl
</refentrytitle>
43 <manvolnum>1</manvolnum>
47 <refname>timedatectl
</refname>
48 <refpurpose>Control the system time and date
</refpurpose>
53 <command>timedatectl
<arg choice=
"opt" rep=
"repeat">OPTIONS
</arg> <arg choice=
"req">COMMAND
</arg></command>
58 <title>Description
</title>
60 <para><command>timedatectl
</command> may be used to query and
61 change the system clock and its settings.
</para>
64 <citerefentry><refentrytitle>systemd-firstboot
</refentrytitle><manvolnum>1</manvolnum></citerefentry>
65 to initialize the system time zone for mounted (but not booted)
70 <title>Options
</title>
72 <para>The following options are understood:
</para>
76 <term><option>--no-ask-password
</option></term>
78 <listitem><para>Do not query the user for authentication for
79 privileged operations.
</para></listitem>
83 <term><option>--adjust-system-clock
</option></term>
85 <listitem><para>If
<command>set-local-rtc
</command> is invoked
86 and this option is passed, the system clock is synchronized
87 from the RTC again, taking the new setting into account.
88 Otherwise, the RTC is synchronized from the system
89 clock.
</para></listitem>
92 <xi:include href=
"user-system-options.xml" xpointer=
"host" />
93 <xi:include href=
"user-system-options.xml" xpointer=
"machine" />
95 <xi:include href=
"standard-options.xml" xpointer=
"help" />
96 <xi:include href=
"standard-options.xml" xpointer=
"version" />
97 <xi:include href=
"standard-options.xml" xpointer=
"no-pager" />
100 <para>The following commands are understood:
</para>
104 <term><command>status
</command></term>
106 <listitem><para>Show current settings of the system clock and RTC,
107 including whether network time synchronization through
108 <filename>systemd-timesyncd.service
</filename> is active. Even if it is
109 inactive, a different service might still synchronize the clock.
114 <term><command>set-time [TIME]
</command></term>
116 <listitem><para>Set the system clock to the specified time.
117 This will also update the RTC time accordingly. The time may
118 be specified in the format
"2012-10-30
119 18:17:16".
</para></listitem>
123 <term><command>set-timezone [TIMEZONE]
</command></term>
125 <listitem><para>Set the system time zone to the specified
126 value. Available timezones can be listed with
127 <command>list-timezones
</command>. If the RTC is configured to
128 be in the local time, this will also update the RTC time. This
129 call will alter the
<filename>/etc/localtime
</filename>
131 <citerefentry><refentrytitle>localtime
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
132 for more information.
</para></listitem>
136 <term><command>list-timezones
</command></term>
138 <listitem><para>List available time zones, one per line.
139 Entries from the list can be set as the system timezone with
140 <command>set-timezone
</command>.
</para></listitem>
144 <term><command>set-local-rtc [BOOL]
</command></term>
146 <listitem><para>Takes a boolean argument. If
147 <literal>0</literal>, the system is configured to maintain the
148 RTC in universal time. If
<literal>1</literal>, it will
149 maintain the RTC in local time instead. Note that maintaining
150 the RTC in the local timezone is not fully supported and will
151 create various problems with time zone changes and daylight
152 saving adjustments. If at all possible, keep the RTC in UTC
153 mode. Note that invoking this will also synchronize the RTC
154 from the system clock, unless
155 <option>--adjust-system-clock
</option> is passed (see above).
156 This command will change the
3rd line of
157 <filename>/etc/adjtime
</filename>, as documented in
158 <citerefentry project='man-pages'
><refentrytitle>hwclock
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
163 <term><command>set-ntp [BOOL]
</command></term>
165 <listitem><para>Takes a boolean argument. Controls whether
166 network time synchronization is active and enabled (if
167 available). This enables and starts, or disables and stops the
168 <filename>systemd-timesyncd.service
</filename> unit. It does
169 not affect the state of any other, unrelated network time
170 synchronization services that might be installed on the
171 system. This command is hence mostly equivalent to:
172 <command>systemctl enable --now
173 systemd-timesyncd.service
</command> and
<command>systemctl
174 disable --now systemd-timesyncd.service
</command>, but is
175 protected by a different access policy.
</para>
177 <para>Note that even if time synchronization is turned off
178 with this command, another unrelated system service might
179 still synchronize the clock with the network. Also note that,
181 <filename>systemd-timesyncd.service
</filename> does more than
182 just network time synchronization, as it ensures a monotonic
183 clock on systems without RTC even if no network is
185 <citerefentry><refentrytitle>systemd-timesyncd.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>
186 for details about this.
</para></listitem>
194 <title>Exit status
</title>
196 <para>On success,
0 is returned, a non-zero failure
197 code otherwise.
</para>
200 <xi:include href=
"less-variables.xml" />
203 <title>Examples
</title>
204 <para>Show current settings:
205 <programlisting>$ timedatectl
206 Local time: Thu
2017-
09-
21 16:
08:
56 CEST
207 Universal time: Thu
2017-
09-
21 14:
08:
56 UTC
208 RTC time: Thu
2017-
09-
21 14:
08:
56
209 Time zone: Europe/Warsaw (CEST, +
0200)
210 System clock synchronized: yes
211 systemd-timesyncd.service active: yes
212 RTC in local TZ: no
</programlisting>
215 <para>Enable network time synchronization:
216 <programlisting>$ timedatectl set-ntp true
217 ==== AUTHENTICATING FOR org.freedesktop.timedate1.set-ntp ===
218 Authentication is required to control whether network time synchronization shall be enabled.
219 Authenticating as: user
221 ==== AUTHENTICATION COMPLETE ===
</programlisting>
223 <programlisting>$ systemctl status systemd-timesyncd.service
224 ● systemd-timesyncd.service - Network Time Synchronization
225 Loaded: loaded (/usr/lib/systemd/system/systemd-timesyncd.service; enabled)
226 Active: active (running) since Mo
2015-
03-
30 14:
20:
38 CEST;
5s ago
227 Docs: man:systemd-timesyncd.service(
8)
228 Main PID:
595 (systemd-timesyn)
229 Status:
"Using Time Server 216.239.38.15:123 (time4.google.com)."
230 CGroup: /system.slice/systemd-timesyncd.service
231 └─
595 /usr/lib/systemd/systemd-timesyncd
237 <title>See Also
</title>
239 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
240 <citerefentry project='man-pages'
><refentrytitle>hwclock
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
241 <citerefentry project='man-pages'
><refentrytitle>date
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
242 <citerefentry><refentrytitle>localtime
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
243 <citerefentry><refentrytitle>systemctl
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
244 <citerefentry><refentrytitle>systemd-timedated.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
245 <citerefentry><refentrytitle>systemd-timesyncd.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
246 <citerefentry><refentrytitle>systemd-firstboot
</refentrytitle><manvolnum>1</manvolnum></citerefentry>