man/timedatectl.xml

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   8   Copyright 2012 Lennart Poettering
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  23
  24 <refentry id="timedatectl" conditional='ENABLE_TIMEDATED'
  25         xmlns:xi="http://www.w3.org/2001/XInclude">
  26
  27         <refentryinfo>
  28                 <title>timedatectl</title>
  29                 <productname>systemd</productname>
  30
  31                 <authorgroup>
  32                         <author>
  33                                 <contrib>Developer</contrib>
  34                                 <firstname>Lennart</firstname>
  35                                 <surname>Poettering</surname>
  36                                 <email>lennart@poettering.net</email>
  37                         </author>
  38                 </authorgroup>
  39         </refentryinfo>
  40
  41         <refmeta>
  42                 <refentrytitle>timedatectl</refentrytitle>
  43                 <manvolnum>1</manvolnum>
  44         </refmeta>
  45
  46         <refnamediv>
  47                 <refname>timedatectl</refname>
  48                 <refpurpose>Control the system time and date</refpurpose>
  49         </refnamediv>
  50
  51         <refsynopsisdiv>
  52                 <cmdsynopsis>
  53                         <command>timedatectl <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="req">COMMAND</arg></command>
  54                 </cmdsynopsis>
  55         </refsynopsisdiv>
  56
  57         <refsect1>
  58                 <title>Description</title>
  59
  60                 <para><command>timedatectl</command> may be used to
  61                 query and change the system clock and its
  62                 settings.</para>
  63         </refsect1>
  64
  65         <refsect1>
  66                 <title>Options</title>
  67
  68                 <para>The following options are understood:</para>
  69
  70                 <variablelist>
  71                         <varlistentry>
  72                                 <term><option>--no-ask-password</option></term>
  73
  74                                 <listitem><para>Do not query the user
  75                                 for authentication for privileged
  76                                 operations.</para></listitem>
  77                         </varlistentry>
  78
  79                         <varlistentry>
  80                                 <term><option>--adjust-system-clock</option></term>
  81
  82                                 <listitem><para>If
  83                                 <command>set-local-rtc</command> is
  84                                 invoked and this option is passed, the
  85                                 system clock is synchronized from the
  86                                 RTC again, taking the new setting into
  87                                 account. Otherwise, the RTC is
  88                                 synchronized from the system
  89                                 clock.</para></listitem>
  90                         </varlistentry>
  91
  92                         <xi:include href="user-system-options.xml" xpointer="host" />
  93                         <xi:include href="user-system-options.xml" xpointer="machine" />
  94
  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" />
  98                 </variablelist>
  99
 100                 <para>The following commands are understood:</para>
 101
 102                 <variablelist>
 103                         <varlistentry>
 104                                 <term><command>status</command></term>
 105
 106                                 <listitem><para>Show current settings
 107                                 of the system clock and
 108                                 RTC.</para></listitem>
 109                         </varlistentry>
 110
 111                         <varlistentry>
 112                                 <term><command>set-time [TIME]</command></term>
 113
 114                                 <listitem><para>Set the system clock
 115                                 to the specified time. This will also
 116                                 update the RTC time accordingly. The time
 117                                 may be specified in the format
 118                                 "2012-10-30
 119                                 18:17:16".</para></listitem>
 120                         </varlistentry>
 121
 122                         <varlistentry>
 123                                 <term><command>set-timezone [TIMEZONE]</command></term>
 124
 125                                 <listitem><para>Set the system time
 126                                 zone to the specified value. Available
 127                                 timezones can be listed with
 128                                 <command>list-timezones</command>. If
 129                                 the RTC is configured to be in the
 130                                 local time, this will also update the
 131                                 RTC time. This call will alter the
 132                                 <filename>/etc/localtime</filename>
 133                                 symlink. See
 134                                 <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 135                                 for more
 136                                 information.</para></listitem>
 137                         </varlistentry>
 138
 139                         <varlistentry>
 140                                 <term><command>list-timezones</command></term>
 141
 142                                 <listitem><para>List available time
 143                                 zones, one per line. Entries from the
 144                                 list can be set as the system
 145                                 timezone with
 146                                 <command>set-timezone</command>.</para></listitem>
 147                         </varlistentry>
 148
 149                         <varlistentry>
 150                                 <term><command>set-local-rtc [BOOL]</command></term>
 151
 152                                 <listitem><para>Takes a boolean
 153                                 argument. If <literal>0</literal>, the
 154                                 system is configured to maintain the
 155                                 RTC in universal time. If
 156                                 <literal>1</literal>, it will maintain
 157                                 the RTC in local time instead. Note
 158                                 that maintaining the RTC in the local
 159                                 timezone is not fully supported and
 160                                 will create various problems with time
 161                                 zone changes and daylight saving
 162                                 adjustments. If at all possible, keep the
 163                                 RTC in UTC mode. Note that invoking this
 164                                 will also synchronize the RTC from the
 165                                 system clock, unless
 166                                 <option>--adjust-system-clock</option> is
 167                                 passed (see above). This command will
 168                                 change the 3rd line of
 169                                 <filename>/etc/adjtime</filename>, as
 170                                 documented in
 171                                 <citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>
 172                         </varlistentry>
 173
 174                         <varlistentry>
 175                                 <term><command>set-ntp [BOOL]</command></term>
 176
 177                                 <listitem><para>Takes a boolean
 178                                 argument. Controls whether NTP based
 179                                 network time synchronization is
 180                                 enabled (if
 181                                 available).</para></listitem>
 182                         </varlistentry>
 183
 184                 </variablelist>
 185
 186         </refsect1>
 187
 188         <refsect1>
 189                 <title>Exit status</title>
 190
 191                 <para>On success, 0 is returned, a non-zero failure
 192                 code otherwise.</para>
 193         </refsect1>
 194
 195         <xi:include href="less-variables.xml" />
 196
 197         <refsect1>
 198                 <title>Examples</title>
 199                 <para>Show current settings:
 200                 <programlisting>$ timedatectl
 201       Local time: Fri, 2012-11-02 09:26:46 CET
 202   Universal time: Fri, 2012-11-02 08:26:46 UTC
 203         RTC time: Fri, 2012-11-02 08:26:45
 204         Timezone: Europe/Warsaw
 205       UTC offset: +0100
 206      NTP enabled: no
 207 NTP synchronized: no
 208  RTC in local TZ: no
 209       DST active: no
 210  Last DST change: CEST → CET, DST became inactive
 211                   Sun, 2012-10-28 02:59:59 CEST
 212                   Sun, 2012-10-28 02:00:00 CET
 213  Next DST change: CET → CEST, DST will become active
 214                   the clock will jump one hour forward
 215                   Sun, 2013-03-31 01:59:59 CET
 216                   Sun, 2013-03-31 03:00:00 CEST</programlisting>
 217                 </para>
 218
 219                 <para>Enable an NTP daemon (chronyd):
 220                 <programlisting>$ timedatectl set-ntp true
 221 ==== AUTHENTICATING FOR org.freedesktop.timedate1.set-ntp ===
 222 Authentication is required to control whether network time synchronization shall be enabled.
 223 Authenticating as: user
 224 Password: ********
 225 ==== AUTHENTICATION COMPLETE ===</programlisting>
 226
 227                 <programlisting>$ systemctl status chronyd.service
 228 chronyd.service - NTP client/server
 229           Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled)
 230           Active: active (running) since Fri, 2012-11-02 09:36:25 CET; 5s ago
 231 ...</programlisting>
 232                 </para>
 233         </refsect1>
 234
 235         <refsect1>
 236                 <title>See Also</title>
 237                 <para>
 238                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 239                         <citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 240                         <citerefentry><refentrytitle>date</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 241                         <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 242                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 243                         <citerefentry><refentrytitle>systemd-timedated.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 244                 </para>
 245         </refsect1>
 246
 247 </refentry>