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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"

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<refentry id="timedatectl">

<refentryinfo>

<title>timedatectl</title>

<productname>systemd</productname>

<authorgroup>

<author>

<contrib>Developer</contrib>

<firstname>Lennart</firstname>

<surname>Poettering</surname>

<email>lennart@poettering.net</email>

</author>

</authorgroup>

</refentryinfo>

<refmeta>

<refentrytitle>timedatectl</refentrytitle>

<manvolnum>1</manvolnum>

</refmeta>

<refnamediv>

<refname>timedatectl</refname>

<refpurpose>Control the system time and date</refpurpose>

</refnamediv>

<refsynopsisdiv>

<cmdsynopsis>

<command>timedatectl <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="req">COMMAND</arg></command>

</cmdsynopsis>

</refsynopsisdiv>

<refsect1>

<title>Description</title>

<para><command>timedatectl</command> may be used to

query and change the system clock and its

settings.</para>

</refsect1>

<refsect1>

<title>Options</title>

<para>The following options are understood:</para>

<variablelist>

<varlistentry>

<term><option>--help</option></term>

<term><option>-h</option></term>

<listitem><para>Prints a short help

text and exits.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--version</option></term>

<listitem><para>Prints a short version

string and exits.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--no-pager</option></term>

<listitem><para>Do not pipe output into a

pager.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--no-ask-password</option></term>

<listitem><para>Don't query the user

for authentication for privileged

operations.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-H</option></term>

<term><option>--host</option></term>

<listitem><para>Execute operation

remotely. Specify a hostname, or

username and hostname separated by @,

to connect to. This will use SSH to

talk to a remote

system.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--adjust-system-clock</option></term>

<listitem><para>If

<command>set-local-rtc</command> is

invoked and this option is passed the

system clock is synchronized from the

RTC again, taking the new setting into

account. Otherwise the RTC is

synchonized from the system

clock.</para></listitem>

</varlistentry>

</variablelist>

<para>The following commands are understood:</para>

<variablelist>

<varlistentry>

<term><command>status</command></term>

<listitem><para>Show current settings

of the system clock and

RTC.</para></listitem>

</varlistentry>

<varlistentry>

<term><command>set-time [TIME]</command></term>

<listitem><para>Set the system clock

to the specified time. This will also

update the RTC time accordingly. The time

may be specified in the format

"2012-10-30

18:17:16".</para></listitem>

</varlistentry>

<varlistentry>

<term><command>set-timezone [TIMEZONE]</command></term>

<listitem><para>Set the system time

zone to the specified value. Available

time zones my be listed with

<command>list-timezones</command>. If

the RTC is configured to be in the

local time this will also update the

RTC time. This call will alter the

<filename>/etc/localtime</filename>

symlink. See

<citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>

for more

information.</para></listitem>

</varlistentry>

<varlistentry>

<term><command>list-timezones</command></term>

<listitem><para>List available time

zones, one per line. Entries from the

list may selected as the system

timezone with

<command>set-timezone</command>.</para></listitem>

</varlistentry>

<varlistentry>

<term><command>set-local-rtc [BOOL]</command></term>

<listitem><para>Takes a boolean

argument. If <literal>0</literal> the

system is configured to maintain the

RTC in universal time, if

<literal>1</literal> it will maintain

the RTC in local time instead. Note

that maintaining the RTC in the local

timezone is is not fully supported and

will create various problems with time

zone changes and daylight saving

adjustments. If at all possible use

RTC in UTC. Note that invoking this

will also synchronize the RTC from the

system clock, unless

<option>--adjust-system-clock</option> is

passed (see above). This command will

change the 3rd line of

<filename>/etc/adjtime</filename>, as

documented in

<citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>

</varlistentry>

<varlistentry>

<term><command>set-ntp [BOOL]</command></term>

<listitem><para>Takes a boolean

argument. Controls whether NTP based

network time synchronization is

enabled (if

available).</para></listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>Exit status</title>

<para>On success 0 is returned, a non-zero failure

code otherwise.</para>

</refsect1>

<refsect1>

<title>Environment</title>

<variablelist>

<varlistentry>

<term><varname>$SYSTEMD_PAGER</varname></term>

<listitem><para>Pager to use when

<option>--no-pager</option> is not given;

overrides <varname>$PAGER</varname>. Setting

this to an empty string or the value

<literal>cat</literal> is equivalent to passing

<option>--no-pager</option>.</para></listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>See Also</title>

<para>

<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>,

<citerefentry><refentrytitle>date</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemd-timedated.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>

</para>

</refsect1>

</refentry>